diff --git a/promql/parse.go b/promql/parse.go
index db94f3418..92f20918b 100644
--- a/promql/parse.go
+++ b/promql/parse.go
@@ -953,11 +953,11 @@ func (p *parser) vectorSelector(name string) *VectorSelector {
 			}
 		}
 		// Set name label matching.
-		matchers = append(matchers, &metric.LabelMatcher{
-			Type:  metric.Equal,
-			Name:  model.MetricNameLabel,
-			Value: model.LabelValue(name),
-		})
+		m, err := metric.NewLabelMatcher(metric.Equal, model.MetricNameLabel, model.LabelValue(name))
+		if err != nil {
+			panic(err) // Must not happen with metric.Equal.
+		}
+		matchers = append(matchers, m)
 	}
 
 	if len(matchers) == 0 {
@@ -967,14 +967,7 @@ func (p *parser) vectorSelector(name string) *VectorSelector {
 	// implicit selection of all metrics (e.g. by a typo).
 	notEmpty := false
 	for _, lm := range matchers {
-		// Matching changes the inner state of the regex and causes reflect.DeepEqual
-		// to return false, which break tests.
-		// Thus, we create a new label matcher for this testing.
-		lm, err := metric.NewLabelMatcher(lm.Type, lm.Name, lm.Value)
-		if err != nil {
-			p.error(err)
-		}
-		if !lm.Match("") {
+		if !lm.MatchesEmptyString() {
 			notEmpty = true
 			break
 		}
diff --git a/promql/parse_test.go b/promql/parse_test.go
index a1599c707..901c99ab3 100644
--- a/promql/parse_test.go
+++ b/promql/parse_test.go
@@ -144,7 +144,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 		},
@@ -154,7 +154,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 		},
@@ -263,13 +263,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{Card: CardOneToOne},
@@ -281,7 +281,7 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &NumberLiteral{1},
@@ -293,7 +293,7 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS:        &NumberLiteral{1},
@@ -307,7 +307,7 @@ var testExpr = []struct {
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 		},
@@ -318,13 +318,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{Card: CardManyToMany},
@@ -336,13 +336,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{Card: CardManyToMany},
@@ -354,13 +354,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{Card: CardManyToMany},
@@ -375,13 +375,13 @@ var testExpr = []struct {
 				LHS: &VectorSelector{
 					Name: "foo",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 					},
 				},
 				RHS: &VectorSelector{
 					Name: "bar",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 					},
 				},
 				VectorMatching: &VectorMatching{Card: CardOneToOne},
@@ -391,13 +391,13 @@ var testExpr = []struct {
 				LHS: &VectorSelector{
 					Name: "bla",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bla"},
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bla"),
 					},
 				},
 				RHS: &VectorSelector{
 					Name: "blub",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "blub"},
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "blub"),
 					},
 				},
 				VectorMatching: &VectorMatching{Card: CardManyToMany},
@@ -416,13 +416,13 @@ var testExpr = []struct {
 					LHS: &VectorSelector{
 						Name: "foo",
 						LabelMatchers: metric.LabelMatchers{
-							{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+							mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 						},
 					},
 					RHS: &VectorSelector{
 						Name: "bar",
 						LabelMatchers: metric.LabelMatchers{
-							{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+							mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 						},
 					},
 					VectorMatching: &VectorMatching{Card: CardManyToMany},
@@ -430,7 +430,7 @@ var testExpr = []struct {
 				RHS: &VectorSelector{
 					Name: "baz",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "baz"},
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "baz"),
 					},
 				},
 				VectorMatching: &VectorMatching{Card: CardManyToMany},
@@ -438,7 +438,7 @@ var testExpr = []struct {
 			RHS: &VectorSelector{
 				Name: "qux",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "qux"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "qux"),
 				},
 			},
 			VectorMatching: &VectorMatching{Card: CardManyToMany},
@@ -451,7 +451,7 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			RHS: &BinaryExpr{
@@ -459,13 +459,13 @@ var testExpr = []struct {
 				LHS: &VectorSelector{
 					Name: "bla",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bla"},
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bla"),
 					},
 				},
 				RHS: &VectorSelector{
 					Name: "blub",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "blub"},
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "blub"),
 					},
 				},
 				VectorMatching: &VectorMatching{
@@ -488,13 +488,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{
@@ -510,13 +510,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{
@@ -532,13 +532,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{
@@ -554,13 +554,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{
@@ -576,13 +576,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{
@@ -597,13 +597,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{
@@ -618,13 +618,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "baz",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "baz"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "baz"),
 				},
 			},
 			VectorMatching: &VectorMatching{
@@ -640,13 +640,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{
@@ -663,13 +663,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{
@@ -685,13 +685,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{
@@ -707,13 +707,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{
@@ -730,13 +730,13 @@ var testExpr = []struct {
 			LHS: &VectorSelector{
 				Name: "foo",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 				},
 			},
 			RHS: &VectorSelector{
 				Name: "bar",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 				},
 			},
 			VectorMatching: &VectorMatching{
@@ -825,7 +825,7 @@ var testExpr = []struct {
 			Name:   "foo",
 			Offset: 0,
 			LabelMatchers: metric.LabelMatchers{
-				{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+				mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 			},
 		},
 	}, {
@@ -834,7 +834,7 @@ var testExpr = []struct {
 			Name:   "foo",
 			Offset: 5 * time.Minute,
 			LabelMatchers: metric.LabelMatchers{
-				{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+				mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 			},
 		},
 	}, {
@@ -843,8 +843,8 @@ var testExpr = []struct {
 			Name:   "foo:bar",
 			Offset: 0,
 			LabelMatchers: metric.LabelMatchers{
-				{Type: metric.Equal, Name: "a", Value: "bc"},
-				{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo:bar"},
+				mustLabelMatcher(metric.Equal, "a", "bc"),
+				mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo:bar"),
 			},
 		},
 	}, {
@@ -853,8 +853,8 @@ var testExpr = []struct {
 			Name:   "foo",
 			Offset: 0,
 			LabelMatchers: metric.LabelMatchers{
-				{Type: metric.Equal, Name: "NaN", Value: "bc"},
-				{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+				mustLabelMatcher(metric.Equal, "NaN", "bc"),
+				mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 			},
 		},
 	}, {
@@ -863,11 +863,11 @@ var testExpr = []struct {
 			Name:   "foo",
 			Offset: 0,
 			LabelMatchers: metric.LabelMatchers{
-				{Type: metric.Equal, Name: "a", Value: "b"},
-				{Type: metric.NotEqual, Name: "foo", Value: "bar"},
+				mustLabelMatcher(metric.Equal, "a", "b"),
+				mustLabelMatcher(metric.NotEqual, "foo", "bar"),
 				mustLabelMatcher(metric.RegexMatch, "test", "test"),
 				mustLabelMatcher(metric.RegexNoMatch, "bar", "baz"),
-				{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+				mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 			},
 		},
 	}, {
@@ -949,7 +949,7 @@ var testExpr = []struct {
 			Offset: 0,
 			Range:  5 * time.Second,
 			LabelMatchers: metric.LabelMatchers{
-				{Type: metric.Equal, Name: model.MetricNameLabel, Value: "test"},
+				mustLabelMatcher(metric.Equal, model.MetricNameLabel, "test"),
 			},
 		},
 	}, {
@@ -959,7 +959,7 @@ var testExpr = []struct {
 			Offset: 0,
 			Range:  5 * time.Minute,
 			LabelMatchers: metric.LabelMatchers{
-				{Type: metric.Equal, Name: model.MetricNameLabel, Value: "test"},
+				mustLabelMatcher(metric.Equal, model.MetricNameLabel, "test"),
 			},
 		},
 	}, {
@@ -969,7 +969,7 @@ var testExpr = []struct {
 			Offset: 5 * time.Minute,
 			Range:  5 * time.Hour,
 			LabelMatchers: metric.LabelMatchers{
-				{Type: metric.Equal, Name: model.MetricNameLabel, Value: "test"},
+				mustLabelMatcher(metric.Equal, model.MetricNameLabel, "test"),
 			},
 		},
 	}, {
@@ -979,7 +979,7 @@ var testExpr = []struct {
 			Offset: 10 * time.Second,
 			Range:  5 * 24 * time.Hour,
 			LabelMatchers: metric.LabelMatchers{
-				{Type: metric.Equal, Name: model.MetricNameLabel, Value: "test"},
+				mustLabelMatcher(metric.Equal, model.MetricNameLabel, "test"),
 			},
 		},
 	}, {
@@ -989,7 +989,7 @@ var testExpr = []struct {
 			Offset: 14 * 24 * time.Hour,
 			Range:  5 * 7 * 24 * time.Hour,
 			LabelMatchers: metric.LabelMatchers{
-				{Type: metric.Equal, Name: model.MetricNameLabel, Value: "test"},
+				mustLabelMatcher(metric.Equal, model.MetricNameLabel, "test"),
 			},
 		},
 	}, {
@@ -999,8 +999,8 @@ var testExpr = []struct {
 			Offset: 3 * 24 * time.Hour,
 			Range:  5 * 365 * 24 * time.Hour,
 			LabelMatchers: metric.LabelMatchers{
-				{Type: metric.Equal, Name: "a", Value: "b"},
-				{Type: metric.Equal, Name: model.MetricNameLabel, Value: "test"},
+				mustLabelMatcher(metric.Equal, "a", "b"),
+				mustLabelMatcher(metric.Equal, model.MetricNameLabel, "test"),
 			},
 		},
 	}, {
@@ -1059,7 +1059,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Grouping: model.LabelNames{"foo"},
@@ -1072,7 +1072,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Grouping: model.LabelNames{"foo"},
@@ -1085,7 +1085,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Grouping: model.LabelNames{"foo", "bar"},
@@ -1097,7 +1097,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Grouping: model.LabelNames{"foo"},
@@ -1109,7 +1109,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Grouping:         model.LabelNames{"foo"},
@@ -1122,7 +1122,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Grouping:         model.LabelNames{"foo"},
@@ -1135,7 +1135,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Grouping: model.LabelNames{"foo"},
@@ -1148,7 +1148,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Grouping: model.LabelNames{"foo"},
@@ -1161,7 +1161,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Grouping: model.LabelNames{"foo"},
@@ -1173,7 +1173,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 		},
@@ -1184,7 +1184,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Grouping: model.LabelNames{"foo"},
@@ -1196,7 +1196,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Grouping: model.LabelNames{},
@@ -1208,7 +1208,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Param: &NumberLiteral{5},
@@ -1220,7 +1220,7 @@ var testExpr = []struct {
 			Expr: &VectorSelector{
 				Name: "some_metric",
 				LabelMatchers: metric.LabelMatchers{
-					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+					mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 				},
 			},
 			Param: &StringLiteral{"value"},
@@ -1288,8 +1288,8 @@ var testExpr = []struct {
 				&VectorSelector{
 					Name: "some_metric",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.NotEqual, Name: "foo", Value: "bar"},
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+						mustLabelMatcher(metric.NotEqual, "foo", "bar"),
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 					},
 				},
 			},
@@ -1302,7 +1302,7 @@ var testExpr = []struct {
 				&MatrixSelector{
 					Name: "some_metric",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 					},
 					Range: 5 * time.Minute,
 				},
@@ -1316,7 +1316,7 @@ var testExpr = []struct {
 				&VectorSelector{
 					Name: "some_metric",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 					},
 				},
 			},
@@ -1329,7 +1329,7 @@ var testExpr = []struct {
 				&VectorSelector{
 					Name: "some_metric",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 					},
 				},
 				&NumberLiteral{5},
@@ -1537,7 +1537,7 @@ var testStatement = []struct {
 							&MatrixSelector{
 								Name: "http_request_count",
 								LabelMatchers: metric.LabelMatchers{
-									{Type: metric.Equal, Name: model.MetricNameLabel, Value: "http_request_count"},
+									mustLabelMatcher(metric.Equal, model.MetricNameLabel, "http_request_count"),
 								},
 								Range: 5 * time.Minute,
 							},
@@ -1553,7 +1553,7 @@ var testStatement = []struct {
 					LHS: &VectorSelector{
 						Name: "dc:http_request:rate5m",
 						LabelMatchers: metric.LabelMatchers{
-							{Type: metric.Equal, Name: model.MetricNameLabel, Value: "dc:http_request:rate5m"},
+							mustLabelMatcher(metric.Equal, model.MetricNameLabel, "dc:http_request:rate5m"),
 						},
 					},
 					RHS: &NumberLiteral{10000},
@@ -1570,8 +1570,8 @@ var testStatement = []struct {
 				Expr: &VectorSelector{
 					Name: "bar",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.Equal, Name: "label1", Value: "value1"},
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+						mustLabelMatcher(metric.Equal, "label1", "value1"),
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 					},
 				},
 				Labels: nil,
@@ -1583,7 +1583,7 @@ var testStatement = []struct {
 					LHS: &VectorSelector{
 						Name: "foo",
 						LabelMatchers: metric.LabelMatchers{
-							{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+							mustLabelMatcher(metric.Equal, model.MetricNameLabel, "foo"),
 						},
 					},
 					RHS: &NumberLiteral{10},
@@ -1604,9 +1604,9 @@ var testStatement = []struct {
 				Expr: &VectorSelector{
 					Name: "bar",
 					LabelMatchers: metric.LabelMatchers{
-						{Type: metric.Equal, Name: "a", Value: "b"},
+						mustLabelMatcher(metric.Equal, "a", "b"),
 						mustLabelMatcher(metric.RegexMatch, "x", "y"),
-						{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+						mustLabelMatcher(metric.Equal, model.MetricNameLabel, "bar"),
 					},
 				},
 				Labels: model.LabelSet{"x": "", "a": "z"},
@@ -1628,7 +1628,7 @@ var testStatement = []struct {
 					LHS: &VectorSelector{
 						Name: "some_metric",
 						LabelMatchers: metric.LabelMatchers{
-							{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
+							mustLabelMatcher(metric.Equal, model.MetricNameLabel, "some_metric"),
 						},
 					},
 					RHS: &NumberLiteral{1},
diff --git a/storage/local/interface.go b/storage/local/interface.go
index be9b31bab..7ecc8ba9e 100644
--- a/storage/local/interface.go
+++ b/storage/local/interface.go
@@ -60,11 +60,11 @@ type Querier interface {
 	NewPreloader() Preloader
 	// MetricsForLabelMatchers returns the metrics from storage that satisfy
 	// the given label matchers. At least one label matcher must be
-	// specified that does not match the empty string. The times from and
-	// through are hints for the storage to optimize the search. The storage
-	// MAY exclude metrics that have no samples in the specified interval
-	// from the returned map. In doubt, specify model.Earliest for from and
-	// model.Latest for through.
+	// specified that does not match the empty string, otherwise an empty
+	// map is returned. The times from and through are hints for the storage
+	// to optimize the search. The storage MAY exclude metrics that have no
+	// samples in the specified interval from the returned map. In doubt,
+	// specify model.Earliest for from and model.Latest for through.
 	MetricsForLabelMatchers(from, through model.Time, matchers ...*metric.LabelMatcher) map[model.Fingerprint]metric.Metric
 	// LastSampleForFingerprint returns the last sample that has been
 	// ingested for the provided fingerprint. If this instance of the
diff --git a/storage/local/storage.go b/storage/local/storage.go
index fd5b6e026..e4308f96e 100644
--- a/storage/local/storage.go
+++ b/storage/local/storage.go
@@ -19,6 +19,7 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"sort"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -59,6 +60,19 @@ const (
 	// other words: if there are no chunks to persist, it doesn't help chunk
 	// eviction if we speed up persistence.)
 	factorMinChunksToPersist = 0.2
+
+	// Threshold for when to stop using LabelMatchers to retrieve and
+	// intersect fingerprints. The rationale here is that looking up more
+	// fingerprints has diminishing returns if we already have narrowed down
+	// the possible fingerprints significantly. It is then easier to simply
+	// lookup the metrics for all the fingerprints and directly compare them
+	// to the matchers. Since a fingerprint lookup for an Equal matcher is
+	// much less expensive, there is a lower threshold for that case.
+	// TODO(beorn7): These numbers need to be tweaked, probably a bit lower.
+	// 5x higher numbers have resulted in slightly worse performance in a
+	// real-life production scenario.
+	fpEqualMatchThreshold = 1000
+	fpOtherMatchThreshold = 10000
 )
 
 var (
@@ -445,27 +459,29 @@ func (s *MemorySeriesStorage) NewPreloader() Preloader {
 	}
 }
 
-// fingerprintsForLabelPairs returns the set of fingerprints that have the given labels.
-// This does not work with empty label values.
-func (s *MemorySeriesStorage) fingerprintsForLabelPairs(pairs ...model.LabelPair) map[model.Fingerprint]struct{} {
-	var result map[model.Fingerprint]struct{}
-	for _, pair := range pairs {
-		intersection := map[model.Fingerprint]struct{}{}
-		fps := s.persistence.fingerprintsForLabelPair(pair)
-		if len(fps) == 0 {
-			return nil
-		}
-		for _, fp := range fps {
-			if _, ok := result[fp]; ok || result == nil {
-				intersection[fp] = struct{}{}
-			}
-		}
-		if len(intersection) == 0 {
-			return nil
-		}
-		result = intersection
+// fingerprintsForLabelPair returns the fingerprints with the given
+// LabelPair. If intersectWith is non-nil, the method will only return
+// fingerprints that are also contained in intersectsWith. If mergeWith is
+// non-nil, the found fingerprints are added to the given map. The returned map
+// is the same as the given one.
+func (s *MemorySeriesStorage) fingerprintsForLabelPair(
+	pair model.LabelPair,
+	mergeWith map[model.Fingerprint]struct{},
+	intersectWith map[model.Fingerprint]struct{},
+) map[model.Fingerprint]struct{} {
+	if mergeWith == nil {
+		mergeWith = map[model.Fingerprint]struct{}{}
 	}
-	return result
+	for _, fp := range s.persistence.fingerprintsForLabelPair(pair) {
+		if intersectWith == nil {
+			mergeWith[fp] = struct{}{}
+			continue
+		}
+		if _, ok := intersectWith[fp]; ok {
+			mergeWith[fp] = struct{}{}
+		}
+	}
+	return mergeWith
 }
 
 // MetricsForLabelMatchers implements Storage.
@@ -473,68 +489,75 @@ func (s *MemorySeriesStorage) MetricsForLabelMatchers(
 	from, through model.Time,
 	matchers ...*metric.LabelMatcher,
 ) map[model.Fingerprint]metric.Metric {
+	sort.Sort(metric.LabelMatchers(matchers))
+
+	if len(matchers) == 0 || matchers[0].MatchesEmptyString() {
+		// No matchers at all or even the best matcher matches the empty string.
+		return nil
+	}
+
 	var (
-		equals  []model.LabelPair
-		filters []*metric.LabelMatcher
+		matcherIdx   int
+		remainingFPs map[model.Fingerprint]struct{}
 	)
-	for _, lm := range matchers {
-		if lm.Type == metric.Equal && lm.Value != "" {
-			equals = append(equals, model.LabelPair{
-				Name:  lm.Name,
-				Value: lm.Value,
-			})
-		} else {
-			filters = append(filters, lm)
+
+	// Equal matchers.
+	for ; matcherIdx < len(matchers) && (remainingFPs == nil || len(remainingFPs) > fpEqualMatchThreshold); matcherIdx++ {
+		m := matchers[matcherIdx]
+		if m.Type != metric.Equal || m.MatchesEmptyString() {
+			break
+		}
+		remainingFPs = s.fingerprintsForLabelPair(
+			model.LabelPair{
+				Name:  m.Name,
+				Value: m.Value,
+			},
+			nil,
+			remainingFPs,
+		)
+		if len(remainingFPs) == 0 {
+			return nil
 		}
 	}
 
-	var resFPs map[model.Fingerprint]struct{}
-	if len(equals) > 0 {
-		resFPs = s.fingerprintsForLabelPairs(equals...)
-	} else {
-		// If we cannot make a preselection based on equality matchers, expanding the other matchers to labels
-		// and intersecting their fingerprints is still likely to be the best choice.
-		var remaining metric.LabelMatchers
-		for _, matcher := range filters {
-			// Equal matches are all empty values.
-			if matcher.Match("") {
-				remaining = append(remaining, matcher)
-				continue
-			}
-			intersection := map[model.Fingerprint]struct{}{}
-
-			matches := matcher.Filter(s.LabelValuesForLabelName(matcher.Name))
-			if len(matches) == 0 {
-				return nil
-			}
-			for _, v := range matches {
-				fps := s.fingerprintsForLabelPairs(model.LabelPair{
-					Name:  matcher.Name,
-					Value: v,
-				})
-				for fp := range fps {
-					if _, ok := resFPs[fp]; ok || resFPs == nil {
-						intersection[fp] = struct{}{}
-					}
-				}
-			}
-			resFPs = intersection
+	// Other matchers.
+	for ; matcherIdx < len(matchers) && (remainingFPs == nil || len(remainingFPs) > fpOtherMatchThreshold); matcherIdx++ {
+		m := matchers[matcherIdx]
+		if m.MatchesEmptyString() {
+			break
+		}
+		lvs := m.Filter(s.LabelValuesForLabelName(m.Name))
+		if len(lvs) == 0 {
+			return nil
+		}
+		fps := map[model.Fingerprint]struct{}{}
+		for _, lv := range lvs {
+			s.fingerprintsForLabelPair(
+				model.LabelPair{
+					Name:  m.Name,
+					Value: lv,
+				},
+				fps,
+				remainingFPs,
+			)
+		}
+		remainingFPs = fps
+		if len(remainingFPs) == 0 {
+			return nil
 		}
-		// The intersected matchers no longer need to be compared against the actual metrics.
-		filters = remaining
 	}
 
 	result := map[model.Fingerprint]metric.Metric{}
-	for fp := range resFPs {
+	for fp := range remainingFPs {
 		s.fpLocker.Lock(fp)
 		if met, _, ok := s.metricForRange(fp, from, through); ok {
 			result[fp] = metric.Metric{Metric: met}
 		}
 		s.fpLocker.Unlock(fp)
 	}
-	for _, matcher := range filters {
+	for _, m := range matchers[matcherIdx:] {
 		for fp, met := range result {
-			if !matcher.Match(met.Metric[matcher.Name]) {
+			if !m.Match(met.Metric[m.Name]) {
 				delete(result, fp)
 			}
 		}
diff --git a/storage/local/storage_test.go b/storage/local/storage_test.go
index fe5f4103c..74694023d 100644
--- a/storage/local/storage_test.go
+++ b/storage/local/storage_test.go
@@ -326,7 +326,10 @@ func TestFingerprintsForLabels(t *testing.T) {
 	}
 
 	for _, mt := range matcherTests {
-		resfps := storage.fingerprintsForLabelPairs(mt.pairs...)
+		var resfps map[model.Fingerprint]struct{}
+		for _, pair := range mt.pairs {
+			resfps = storage.fingerprintsForLabelPair(pair, nil, resfps)
+		}
 		if len(mt.expected) != len(resfps) {
 			t.Fatalf("expected %d matches for %q, found %d", len(mt.expected), mt.pairs, len(resfps))
 		}
@@ -467,7 +470,9 @@ func TestRetentionCutoff(t *testing.T) {
 	s.WaitForIndexing()
 
 	var fp model.Fingerprint
-	for f := range s.fingerprintsForLabelPairs(model.LabelPair{Name: "job", Value: "test"}) {
+	for f := range s.fingerprintsForLabelPair(model.LabelPair{
+		Name: "job", Value: "test",
+	}, nil, nil) {
 		fp = f
 		break
 	}
@@ -539,7 +544,9 @@ func TestDropMetrics(t *testing.T) {
 	s.persistence.archiveMetric(fpToBeArchived, m3, 0, insertStart.Add(time.Duration(N-1)*time.Millisecond))
 	s.fpLocker.Unlock(fpToBeArchived)
 
-	fps := s.fingerprintsForLabelPairs(model.LabelPair{Name: model.MetricNameLabel, Value: "test"})
+	fps := s.fingerprintsForLabelPair(model.LabelPair{
+		Name: model.MetricNameLabel, Value: "test",
+	}, nil, nil)
 	if len(fps) != 3 {
 		t.Errorf("unexpected number of fingerprints: %d", len(fps))
 	}
@@ -549,9 +556,9 @@ func TestDropMetrics(t *testing.T) {
 	s.DropMetricsForFingerprints(fpList[0])
 	s.WaitForIndexing()
 
-	fps2 := s.fingerprintsForLabelPairs(model.LabelPair{
+	fps2 := s.fingerprintsForLabelPair(model.LabelPair{
 		Name: model.MetricNameLabel, Value: "test",
-	})
+	}, nil, nil)
 	if len(fps2) != 2 {
 		t.Errorf("unexpected number of fingerprints: %d", len(fps2))
 	}
@@ -576,9 +583,9 @@ func TestDropMetrics(t *testing.T) {
 	s.DropMetricsForFingerprints(fpList...)
 	s.WaitForIndexing()
 
-	fps3 := s.fingerprintsForLabelPairs(model.LabelPair{
+	fps3 := s.fingerprintsForLabelPair(model.LabelPair{
 		Name: model.MetricNameLabel, Value: "test",
-	})
+	}, nil, nil)
 	if len(fps3) != 0 {
 		t.Errorf("unexpected number of fingerprints: %d", len(fps3))
 	}
@@ -658,7 +665,9 @@ func TestQuarantineMetric(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	fps := s.fingerprintsForLabelPairs(model.LabelPair{Name: model.MetricNameLabel, Value: "test"})
+	fps := s.fingerprintsForLabelPair(model.LabelPair{
+		Name: model.MetricNameLabel, Value: "test",
+	}, nil, nil)
 	if len(fps) != 3 {
 		t.Errorf("unexpected number of fingerprints: %d", len(fps))
 	}
@@ -670,9 +679,9 @@ func TestQuarantineMetric(t *testing.T) {
 	time.Sleep(time.Second) // Give time to quarantine. TODO(beorn7): Find a better way to wait.
 	s.WaitForIndexing()
 
-	fps2 := s.fingerprintsForLabelPairs(model.LabelPair{
+	fps2 := s.fingerprintsForLabelPair(model.LabelPair{
 		Name: model.MetricNameLabel, Value: "test",
-	})
+	}, nil, nil)
 	if len(fps2) != 2 {
 		t.Errorf("unexpected number of fingerprints: %d", len(fps2))
 	}
diff --git a/storage/metric/matcher.go b/storage/metric/matcher.go
index e4404917c..8b362db79 100644
--- a/storage/metric/matcher.go
+++ b/storage/metric/matcher.go
@@ -16,6 +16,7 @@ package metric
 import (
 	"fmt"
 	"regexp"
+	"strings"
 
 	"github.com/prometheus/common/model"
 )
@@ -44,15 +45,23 @@ func (m MatchType) String() string {
 	panic("unknown match type")
 }
 
-// LabelMatchers is a slice of LabelMatcher objects.
+// LabelMatchers is a slice of LabelMatcher objects. By implementing the
+// sort.Interface, it is sortable by cardinality score, i.e. after sorting, the
+// LabelMatcher that is expected to yield the fewest matches is first in the
+// slice, and LabelMatchers that match the empty string are last.
 type LabelMatchers []*LabelMatcher
 
-// LabelMatcher models the matching of a label.
+func (lms LabelMatchers) Len() int           { return len(lms) }
+func (lms LabelMatchers) Swap(i, j int)      { lms[i], lms[j] = lms[j], lms[i] }
+func (lms LabelMatchers) Less(i, j int) bool { return lms[i].score < lms[j].score }
+
+// LabelMatcher models the matching of a label. Create with NewLabelMatcher.
 type LabelMatcher struct {
 	Type  MatchType
 	Name  model.LabelName
 	Value model.LabelValue
 	re    *regexp.Regexp
+	score float64 // Cardinality score, between 0 and 1, 0 is lowest cardinality.
 }
 
 // NewLabelMatcher returns a LabelMatcher object ready to use.
@@ -69,9 +78,96 @@ func NewLabelMatcher(matchType MatchType, name model.LabelName, value model.Labe
 		}
 		m.re = re
 	}
+	m.calculateScore()
 	return m, nil
 }
 
+// calculateScore is a helper method only called in the constructor. It
+// calculates the cardinality score upfront, so that sorting by it is faster and
+// doesn't change internal state of the matcher.
+//
+// The score is based on a pretty bad but still quite helpful heuristics for
+// now. Note that this is an interim solution until the work in progress to
+// properly intersect matchers is complete. We intend to not invest any further
+// effort into tweaking the score calculation, as this could easily devolve into
+// a rabbit hole.
+//
+// The heuristics works along the following lines:
+//
+// - A matcher that is known to match nothing would have a score of 0. (This
+//   case doesn't happen in the scope of this method.)
+//
+// - A matcher that matches the empty string has a score of 1.
+//
+// - Equal matchers have a score <= 0.5. The order in score for other matchers
+//   are RegexMatch, RegexNoMatch, NotEqual.
+//
+// - There are a number of score adjustments for known "magic" parts, like
+//   instance labels, metric names containing a colon (which are probably
+//   recording rules) and such.
+//
+// - On top, there is a tiny adjustment for the length of the matcher, following
+//   the blunt expectation that a long label name and/or value is more specific
+//   and will therefore have a lower cardinality.
+//
+// To reiterate on the above: PLEASE RESIST THE TEMPTATION TO TWEAK THIS
+// METHOD. IT IS "MAGIC" ENOUGH ALREADY AND WILL GO AWAY WITH THE UPCOMING MORE
+// POWERFUL INDEXING.
+func (m *LabelMatcher) calculateScore() {
+	if m.Match("") {
+		m.score = 1
+		return
+	}
+	// lengthCorrection is between 0 (for length 0) and 0.1 (for length +Inf).
+	lengthCorrection := 0.1 * (1 - 1/float64(len(m.Name)+len(m.Value)+1))
+	switch m.Type {
+	case Equal:
+		m.score = 0.3 - lengthCorrection
+	case RegexMatch:
+		m.score = 0.6 - lengthCorrection
+	case RegexNoMatch:
+		m.score = 0.8 + lengthCorrection
+	case NotEqual:
+		m.score = 0.9 + lengthCorrection
+	}
+	if m.Type != Equal {
+		// Don't bother anymore in this case.
+		return
+	}
+	switch m.Name {
+	case model.InstanceLabel:
+		// Matches only metrics from a single instance, which clearly
+		// limits the damage.
+		m.score -= 0.2
+	case model.JobLabel:
+		// The usual case is a relatively low number of jobs with many
+		// metrics each.
+		m.score += 0.1
+	case model.BucketLabel, model.QuantileLabel:
+		// Magic labels for buckets and quantiles will match copiously.
+		m.score += 0.2
+	case model.MetricNameLabel:
+		if strings.Contains(string(m.Value), ":") {
+			// Probably a recording rule with limited cardinality.
+			m.score -= 0.1
+			return
+		}
+		if m.Value == "up" || m.Value == "scrape_duration_seconds" {
+			// Synthetic metrics which are contained in every scrape
+			// exactly once.  There might be less frequent metric
+			// names, but the worst case is limited here, so give it
+			// a bump.
+			m.score -= 0.05
+			return
+		}
+	}
+}
+
+// MatchesEmptyString returns true if the LabelMatcher matches the empty string.
+func (m *LabelMatcher) MatchesEmptyString() bool {
+	return m.score >= 1
+}
+
 func (m *LabelMatcher) String() string {
 	return fmt.Sprintf("%s%s%q", m.Name, m.Type, m.Value)
 }
diff --git a/storage/metric/matcher_test.go b/storage/metric/matcher_test.go
index dd5629526..0038cee43 100644
--- a/storage/metric/matcher_test.go
+++ b/storage/metric/matcher_test.go
@@ -14,7 +14,12 @@
 package metric
 
 import (
+	"math/rand"
+	"reflect"
+	"sort"
 	"testing"
+
+	"github.com/prometheus/common/model"
 )
 
 func TestAnchoredMatcher(t *testing.T) {
@@ -30,3 +35,39 @@ func TestAnchoredMatcher(t *testing.T) {
 		t.Errorf("Unexpected match for %q", "fooo")
 	}
 }
+
+func TestLabelMatchersSort(t *testing.T) {
+	// Line up Matchers in expected order:
+	want := LabelMatchers{
+		mustNewLabelMatcher(Equal, model.InstanceLabel, "not empty"),
+		mustNewLabelMatcher(Equal, model.MetricNameLabel, "a:recording:rule"),
+		mustNewLabelMatcher(Equal, model.MetricNameLabel, "up"),
+		mustNewLabelMatcher(Equal, "nothing_special but much longer", "not empty"),
+		mustNewLabelMatcher(Equal, "nothing_special", "not empty but longer"),
+		mustNewLabelMatcher(Equal, "nothing_special", "not empty"),
+		mustNewLabelMatcher(Equal, model.JobLabel, "not empty"),
+		mustNewLabelMatcher(Equal, model.BucketLabel, "not empty"),
+		mustNewLabelMatcher(RegexMatch, "irrelevant", "does not match empty string and is longer"),
+		mustNewLabelMatcher(RegexMatch, "irrelevant", "does not match empty string"),
+		mustNewLabelMatcher(RegexNoMatch, "irrelevant", "(matches empty string)?"),
+		mustNewLabelMatcher(RegexNoMatch, "irrelevant", "(matches empty string with a longer expression)?"),
+		mustNewLabelMatcher(NotEqual, "irrelevant", ""),
+		mustNewLabelMatcher(Equal, "irrelevant", ""),
+	}
+	got := make(LabelMatchers, len(want))
+	for i, j := range rand.Perm(len(want)) {
+		got[i] = want[j]
+	}
+	sort.Sort(got)
+	if !reflect.DeepEqual(want, got) {
+		t.Errorf("unexpected sorting of matchers, got %v, want %v", got, want)
+	}
+}
+
+func mustNewLabelMatcher(mt MatchType, name model.LabelName, val model.LabelValue) *LabelMatcher {
+	m, err := NewLabelMatcher(mt, name, val)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}