diff --git a/runners/spark/src/main/java/org/apache/beam/runners/spark/translation/GroupNonMergingWindowsFunctions.java b/runners/spark/src/main/java/org/apache/beam/runners/spark/translation/GroupNonMergingWindowsFunctions.java
index 0a8e7d8a159b..2461d5cc8d66 100644
--- a/runners/spark/src/main/java/org/apache/beam/runners/spark/translation/GroupNonMergingWindowsFunctions.java
+++ b/runners/spark/src/main/java/org/apache/beam/runners/spark/translation/GroupNonMergingWindowsFunctions.java
@@ -275,17 +275,18 @@ JavaRDD<WindowedValue<KV<K, Iterable<V>>>> groupByKeyInGlobalWindow(
                 new Tuple2<>(
                     new ByteArray(CoderHelpers.toByteArray(wv.getValue().getKey(), keyCoder)),
                     CoderHelpers.toByteArray(wv.getValue().getValue(), valueCoder)));
-    return rawKeyValues
-        .groupByKey()
-        .map(
-            kvs ->
-                WindowedValue.timestampedValueInGlobalWindow(
-                    KV.of(
-                        CoderHelpers.fromByteArray(kvs._1.getValue(), keyCoder),
-                        Iterables.transform(
-                            kvs._2,
-                            encodedValue -> CoderHelpers.fromByteArray(encodedValue, valueCoder))),
-                    GlobalWindow.INSTANCE.maxTimestamp(),
-                    PaneInfo.ON_TIME_AND_ONLY_FIRING));
+
+    JavaPairRDD<ByteArray, Iterable<byte[]>> grouped =
+        (partitioner == null) ? rawKeyValues.groupByKey() : rawKeyValues.groupByKey(partitioner);
+    return grouped.map(
+        kvs ->
+            WindowedValue.timestampedValueInGlobalWindow(
+                KV.of(
+                    CoderHelpers.fromByteArray(kvs._1.getValue(), keyCoder),
+                    Iterables.transform(
+                        kvs._2,
+                        encodedValue -> CoderHelpers.fromByteArray(encodedValue, valueCoder))),
+                GlobalWindow.INSTANCE.maxTimestamp(),
+                PaneInfo.ON_TIME_AND_ONLY_FIRING));
   }
 }
diff --git a/runners/spark/src/test/java/org/apache/beam/runners/spark/translation/GroupNonMergingWindowsFunctionsTest.java b/runners/spark/src/test/java/org/apache/beam/runners/spark/translation/GroupNonMergingWindowsFunctionsTest.java
index fd299924af91..ed7bc078564e 100644
--- a/runners/spark/src/test/java/org/apache/beam/runners/spark/translation/GroupNonMergingWindowsFunctionsTest.java
+++ b/runners/spark/src/test/java/org/apache/beam/runners/spark/translation/GroupNonMergingWindowsFunctionsTest.java
@@ -18,6 +18,12 @@
 package org.apache.beam.runners.spark.translation;
 
 import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 import java.util.Arrays;
 import java.util.Iterator;
@@ -39,6 +45,9 @@
 import org.apache.beam.sdk.values.KV;
 import org.apache.beam.sdk.values.WindowingStrategy;
 import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.primitives.Bytes;
+import org.apache.spark.Partitioner;
+import org.apache.spark.api.java.JavaPairRDD;
+import org.apache.spark.api.java.JavaRDD;
 import org.joda.time.Duration;
 import org.joda.time.Instant;
 import org.junit.Assert;
@@ -112,6 +121,54 @@ public void testGbkIteratorValuesCannotBeReiterated() throws Coder.NonDeterminis
     }
   }
 
+  @Test
+  @SuppressWarnings({"rawtypes", "unchecked"})
+  public void testGroupByKeyInGlobalWindowWithPartitioner() {
+    // mocking
+    Partitioner mockPartitioner = mock(Partitioner.class);
+    JavaRDD mockRdd = mock(JavaRDD.class);
+    Coder mockKeyCoder = mock(Coder.class);
+    Coder mockValueCoder = mock(Coder.class);
+    JavaPairRDD mockRawKeyValues = mock(JavaPairRDD.class);
+    JavaPairRDD mockGrouped = mock(JavaPairRDD.class);
+
+    when(mockRdd.mapToPair(any())).thenReturn(mockRawKeyValues);
+    when(mockRawKeyValues.groupByKey(any(Partitioner.class)))
+        .thenAnswer(
+            invocation -> {
+              Partitioner partitioner = invocation.getArgument(0);
+              assertEquals(partitioner, mockPartitioner);
+              return mockGrouped;
+            });
+    when(mockGrouped.map(any())).thenReturn(mock(JavaRDD.class));
+
+    GroupNonMergingWindowsFunctions.groupByKeyInGlobalWindow(
+        mockRdd, mockKeyCoder, mockValueCoder, mockPartitioner);
+
+    verify(mockRawKeyValues, never()).groupByKey();
+    verify(mockRawKeyValues, times(1)).groupByKey(any(Partitioner.class));
+  }
+
+  @Test
+  @SuppressWarnings({"rawtypes", "unchecked"})
+  public void testGroupByKeyInGlobalWindowWithoutPartitioner() {
+    // mocking
+    JavaRDD mockRdd = mock(JavaRDD.class);
+    Coder mockKeyCoder = mock(Coder.class);
+    Coder mockValueCoder = mock(Coder.class);
+    JavaPairRDD mockRawKeyValues = mock(JavaPairRDD.class);
+    JavaPairRDD mockGrouped = mock(JavaPairRDD.class);
+
+    when(mockRdd.mapToPair(any())).thenReturn(mockRawKeyValues);
+    when(mockRawKeyValues.groupByKey()).thenReturn(mockGrouped);
+
+    GroupNonMergingWindowsFunctions.groupByKeyInGlobalWindow(
+        mockRdd, mockKeyCoder, mockValueCoder, null);
+
+    verify(mockRawKeyValues, times(1)).groupByKey();
+    verify(mockRawKeyValues, never()).groupByKey(any(Partitioner.class));
+  }
+
   private GroupByKeyIterator<String, Integer, GlobalWindow> createGbkIterator()
       throws Coder.NonDeterministicException {
     return createGbkIterator(