diff --git a/web/api/v1/api.go b/web/api/v1/api.go
index 40fb68b162..9ceaa8c3f2 100644
--- a/web/api/v1/api.go
+++ b/web/api/v1/api.go
@@ -768,15 +768,21 @@ func (api *API) series(r *http.Request) (result apiFuncResult) {
 		End:   timestamp.FromTime(end),
 		Func:  "series", // There is no series function, this token is used for lookups that don't need samples.
 	}
+	var set storage.SeriesSet
 
-	var sets []storage.SeriesSet
-	for _, mset := range matcherSets {
-		// We need to sort this select results to merge (deduplicate) the series sets later.
-		s := q.Select(true, hints, mset...)
-		sets = append(sets, s)
+	if len(matcherSets) > 1 {
+		var sets []storage.SeriesSet
+		for _, mset := range matcherSets {
+			// We need to sort this select results to merge (deduplicate) the series sets later.
+			s := q.Select(true, hints, mset...)
+			sets = append(sets, s)
+		}
+		set = storage.NewMergeSeriesSet(sets, storage.ChainedSeriesMerge)
+	} else {
+		// At this point at least one match exists.
+		set = q.Select(false, hints, matcherSets[0]...)
 	}
 
-	set := storage.NewMergeSeriesSet(sets, storage.ChainedSeriesMerge)
 	metrics := []labels.Labels{}
 	for set.Next() {
 		metrics = append(metrics, set.At().Labels())