diff --git a/docs/changelog/135734.yaml b/docs/changelog/135734.yaml
new file mode 100644
index 0000000000000..b02abfa20e53f
--- /dev/null
+++ b/docs/changelog/135734.yaml
@@ -0,0 +1,5 @@
+pr: 135734
+summary: Fill in topn values if competitive
+area: ES|QL
+type: enhancement
+issues: []
diff --git a/x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/operator/topn/TopNOperator.java b/x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/operator/topn/TopNOperator.java
index ba522bf130f82..1bc6434786675 100644
--- a/x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/operator/topn/TopNOperator.java
+++ b/x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/operator/topn/TopNOperator.java
@@ -199,15 +199,7 @@ static final class RowFiller {
             }
         }
 
-        /**
-         * Fill a {@link Row} for {@code position}.
-         */
-        void row(int position, Row destination) {
-            writeKey(position, destination);
-            writeValues(position, destination);
-        }
-
-        private void writeKey(int position, Row row) {
+        void writeKey(int position, Row row) {
             int orderByCompositeKeyCurrentPosition = 0;
             for (int i = 0; i < keyFactories.length; i++) {
                 int valueAsBytesSize = keyFactories[i].extractor.writeKey(row.keys, position);
@@ -217,7 +209,7 @@ private void writeKey(int position, Row row) {
             }
         }
 
-        private void writeValues(int position, Row destination) {
+        void writeValues(int position, Row destination) {
             for (ValueExtractor e : valueExtractors) {
                 var refCounted = e.getRefCountedForShard(position);
                 if (refCounted != null) {
@@ -416,15 +408,28 @@ public void addInput(Page page) {
                     spare.values.clear();
                     spare.clearRefCounters();
                 }
-                rowFiller.row(i, spare);
+                rowFiller.writeKey(i, spare);
 
                 // When rows are very long, appending the values one by one can lead to lots of allocations.
                 // To avoid this, pre-allocate at least as much size as in the last seen row.
                 // Let the pre-allocation size decay in case we only have 1 huge row and smaller rows otherwise.
                 spareKeysPreAllocSize = Math.max(spare.keys.length(), spareKeysPreAllocSize / 2);
-                spareValuesPreAllocSize = Math.max(spare.values.length(), spareValuesPreAllocSize / 2);
 
-                spare = inputQueue.insertWithOverflow(spare);
+                // This is `inputQueue.insertWithOverflow` with followed by filling in the value only if we inserted.
+                if (inputQueue.size() < inputQueue.topCount) {
+                    // Heap not yet full, just add elements
+                    rowFiller.writeValues(i, spare);
+                    spareValuesPreAllocSize = Math.max(spare.values.length(), spareValuesPreAllocSize / 2);
+                    inputQueue.add(spare);
+                    spare = null;
+                } else if (inputQueue.lessThan(inputQueue.top(), spare)) {
+                    // Heap full AND this node fit in it.
+                    Row nextSpare = inputQueue.top();
+                    rowFiller.writeValues(i, spare);
+                    spareValuesPreAllocSize = Math.max(spare.values.length(), spareValuesPreAllocSize / 2);
+                    inputQueue.updateTop(spare);
+                    spare = nextSpare;
+                }
             }
         } finally {
             page.releaseBlocks();
diff --git a/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/operator/topn/TopNOperatorTests.java b/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/operator/topn/TopNOperatorTests.java
index 97f301e252fd2..7d48b79ab12c5 100644
--- a/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/operator/topn/TopNOperatorTests.java
+++ b/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/operator/topn/TopNOperatorTests.java
@@ -92,7 +92,6 @@
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.hasSize;
-import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.lessThan;
 import static org.hamcrest.Matchers.lessThanOrEqualTo;
 
@@ -470,7 +469,8 @@ private TopNOperator.Row row(
             page
         );
         TopNOperator.Row row = new TopNOperator.Row(nonBreakingBigArrays().breakerService().getBreaker("request"), sortOrders, 0, 0);
-        rf.row(position, row);
+        rf.writeKey(position, row);
+        rf.writeValues(position, row);
         return row;
     }
 
@@ -1468,6 +1468,7 @@ public void testRowResizes() {
         );
         List<ElementType> types = Collections.nCopies(columns, INT);
         List<TopNEncoder> encoders = Collections.nCopies(columns, DEFAULT_UNSORTABLE);
+        boolean asc = randomBoolean();
         try (
             TopNOperator op = new TopNOperator(
                 driverContext().blockFactory(),
@@ -1475,7 +1476,7 @@ public void testRowResizes() {
                 10,
                 types,
                 encoders,
-                List.of(new TopNOperator.SortOrder(0, randomBoolean(), randomBoolean())),
+                List.of(new TopNOperator.SortOrder(0, asc, randomBoolean())),
                 randomPageSize()
             )
         ) {
@@ -1491,7 +1492,8 @@ public void testRowResizes() {
 
             // 105 are from the objects
             // 1 is for the min-heap itself
-            assertThat(breaker.getMemoryRequestCount(), is(106L));
+            // -1 IF we're sorting ascending. We encode one less value.
+            assertThat(breaker.getMemoryRequestCount(), equalTo(asc ? 105L : 106L));
         }
     }