diff --git a/hadoop-mapreduce-project/CHANGES.txt b/hadoop-mapreduce-project/CHANGES.txt
index 088ac50f72c..f0c4d253986 100644
--- a/hadoop-mapreduce-project/CHANGES.txt
+++ b/hadoop-mapreduce-project/CHANGES.txt
@@ -613,6 +613,8 @@ Release 0.23.5 - UNRELEASED
     MAPREDUCE-4730. Fix Reducer's EventFetcher to scale the map-completion
     requests slowly to avoid HADOOP-8942. (Jason Lowe via vinodkv)
 
+    MAPREDUCE-4748. Invalid event: T_ATTEMPT_SUCCEEDED at SUCCEEDED. (jlowe)
+
 Release 0.23.4 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/job/impl/TaskImpl.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/job/impl/TaskImpl.java
index 830603b77e3..141559ce642 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/job/impl/TaskImpl.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/job/impl/TaskImpl.java
@@ -203,7 +203,10 @@ TaskEventType.T_ATTEMPT_KILLED, new RetroactiveKilledTransition())
     .addTransition(
         TaskStateInternal.SUCCEEDED, TaskStateInternal.SUCCEEDED,
         EnumSet.of(TaskEventType.T_ADD_SPEC_ATTEMPT,
-            TaskEventType.T_ATTEMPT_LAUNCHED))
+            TaskEventType.T_ATTEMPT_COMMIT_PENDING,
+            TaskEventType.T_ATTEMPT_LAUNCHED,
+            TaskEventType.T_ATTEMPT_SUCCEEDED,
+            TaskEventType.T_KILL))
 
     // Transitions from FAILED state        
     .addTransition(TaskStateInternal.FAILED, TaskStateInternal.FAILED,
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/job/impl/TestTaskImpl.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/job/impl/TestTaskImpl.java
index da21dd79db7..87f93c676e8 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/job/impl/TestTaskImpl.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/job/impl/TestTaskImpl.java
@@ -418,6 +418,21 @@ public void testKillRunningTaskAttempt() {
     killRunningTaskAttempt(getLastAttempt().getAttemptId());    
   }
 
+  @Test
+  public void testKillSuccessfulTask() {
+    LOG.info("--- START: testKillSuccesfulTask ---");
+    mockTask = createMockTask(TaskType.MAP);
+    TaskId taskId = getNewTaskID();
+    scheduleTaskAttempt(taskId);
+    launchTaskAttempt(getLastAttempt().getAttemptId());
+    commitTaskAttempt(getLastAttempt().getAttemptId());
+    mockTask.handle(new TaskTAttemptEvent(getLastAttempt().getAttemptId(),
+        TaskEventType.T_ATTEMPT_SUCCEEDED));
+    assertTaskSucceededState();
+    mockTask.handle(new TaskEvent(taskId, TaskEventType.T_KILL));
+    assertTaskSucceededState();
+  }
+
   @Test 
   public void testTaskProgress() {
     LOG.info("--- START: testTaskProgress ---");
@@ -485,7 +500,8 @@ public void testFailureDuringTaskAttemptCommit() {
     assertTaskSucceededState();
   }
   
-  private void runSpeculativeTaskAttemptSucceedsEvenIfFirstFails(TaskEventType failEvent) {
+  private void runSpeculativeTaskAttemptSucceeds(
+      TaskEventType firstAttemptFinishEvent) {
     TaskId taskId = getNewTaskID();
     scheduleTaskAttempt(taskId);
     launchTaskAttempt(getLastAttempt().getAttemptId());
@@ -502,9 +518,9 @@ private void runSpeculativeTaskAttemptSucceedsEvenIfFirstFails(TaskEventType fai
     // The task should now have succeeded
     assertTaskSucceededState();
     
-    // Now fail the first task attempt, after the second has succeeded
+    // Now complete the first task attempt, after the second has succeeded
     mockTask.handle(new TaskTAttemptEvent(taskAttempts.get(0).getAttemptId(), 
-        failEvent));
+        firstAttemptFinishEvent));
     
     // The task should still be in the succeeded state
     assertTaskSucceededState();
@@ -513,25 +529,36 @@ private void runSpeculativeTaskAttemptSucceedsEvenIfFirstFails(TaskEventType fai
   @Test
   public void testMapSpeculativeTaskAttemptSucceedsEvenIfFirstFails() {
     mockTask = createMockTask(TaskType.MAP);        
-    runSpeculativeTaskAttemptSucceedsEvenIfFirstFails(TaskEventType.T_ATTEMPT_FAILED);
+    runSpeculativeTaskAttemptSucceeds(TaskEventType.T_ATTEMPT_FAILED);
   }
 
   @Test
   public void testReduceSpeculativeTaskAttemptSucceedsEvenIfFirstFails() {
     mockTask = createMockTask(TaskType.REDUCE);        
-    runSpeculativeTaskAttemptSucceedsEvenIfFirstFails(TaskEventType.T_ATTEMPT_FAILED);
+    runSpeculativeTaskAttemptSucceeds(TaskEventType.T_ATTEMPT_FAILED);
   }
   
   @Test
   public void testMapSpeculativeTaskAttemptSucceedsEvenIfFirstIsKilled() {
     mockTask = createMockTask(TaskType.MAP);        
-    runSpeculativeTaskAttemptSucceedsEvenIfFirstFails(TaskEventType.T_ATTEMPT_KILLED);
+    runSpeculativeTaskAttemptSucceeds(TaskEventType.T_ATTEMPT_KILLED);
   }
 
   @Test
   public void testReduceSpeculativeTaskAttemptSucceedsEvenIfFirstIsKilled() {
     mockTask = createMockTask(TaskType.REDUCE);        
-    runSpeculativeTaskAttemptSucceedsEvenIfFirstFails(TaskEventType.T_ATTEMPT_KILLED);
+    runSpeculativeTaskAttemptSucceeds(TaskEventType.T_ATTEMPT_KILLED);
   }
 
+  @Test
+  public void testMultipleTaskAttemptsSucceed() {
+    mockTask = createMockTask(TaskType.MAP);
+    runSpeculativeTaskAttemptSucceeds(TaskEventType.T_ATTEMPT_SUCCEEDED);
+  }
+
+  @Test
+  public void testCommitAfterSucceeds() {
+    mockTask = createMockTask(TaskType.REDUCE);
+    runSpeculativeTaskAttemptSucceeds(TaskEventType.T_ATTEMPT_COMMIT_PENDING);
+  }
 }