diff --git a/src/server/game/AI/CoreAI/PetAI.cpp b/src/server/game/AI/CoreAI/PetAI.cpp
index 78c22e74f4..47cc4d1250 100644
--- a/src/server/game/AI/CoreAI/PetAI.cpp
+++ b/src/server/game/AI/CoreAI/PetAI.cpp
@@ -106,8 +106,12 @@ void PetAI::UpdateAI(const uint32 diff)
         // Check before attacking to prevent pets from leaving stay position
         if (me->GetCharmInfo()->HasCommandState(COMMAND_STAY))
         {
+            // Case where pet was put on stay after "attack" was clicked and it gets attacked by
+            //  another creature. Pet can switch target if victim is out of range.
             if (me->GetCharmInfo()->IsCommandAttack() || (me->GetCharmInfo()->IsAtStay() && me->IsWithinMeleeRange(me->getVictim())))
                 DoMeleeAttackIfReady();
+            else if (me->GetCharmInfo()->IsCommandAttack() || (me->GetCharmInfo()->IsAtStay() && me->IsWithinMeleeRange(me->getAttackerForHelper())))
+                DoAttack(me->getAttackerForHelper(), false);
         }
         else
             DoMeleeAttackIfReady();
diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index d4b276fd2d..4252bf1cb1 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -12136,7 +12136,10 @@ void Unit::CombatStart(Unit* target, bool initialAggro)
         if (!target->isInCombat() && target->GetTypeId() != TYPEID_PLAYER
             && !target->ToCreature()->HasReactState(REACT_PASSIVE) && target->ToCreature()->IsAIEnabled)
         {
-            target->ToCreature()->AI()->AttackStart(this);
+            if (target->isPet())
+                target->ToCreature()->AI()->AttackedBy(this); // PetAI has special handler before AttackStart()
+            else
+                target->ToCreature()->AI()->AttackStart(this);
         }
 
         SetInCombatWith(target);
diff --git a/src/server/game/Entities/Unit/Unit.h b/src/server/game/Entities/Unit/Unit.h
index 3053d0018d..8cb0f43490 100644
--- a/src/server/game/Entities/Unit/Unit.h
+++ b/src/server/game/Entities/Unit/Unit.h
@@ -1261,12 +1261,22 @@ class Unit : public WorldObject
         }
         Unit* getAttackerForHelper() const                 // If someone wants to help, who to give them
         {
-            if (getVictim() != NULL)
-                return getVictim();
+            if (isPet())
+            {
+                if (!m_attackers.empty())
+                    return *(m_attackers.begin());
 
-            if (!m_attackers.empty())
-                return *(m_attackers.begin());
+                if (getVictim() != NULL)
+                    return getVictim();
+            }
+            else
+            {
+                if (getVictim() != NULL)
+                    return getVictim();
 
+                if (!m_attackers.empty())
+                    return *(m_attackers.begin());
+            }
             return NULL;
         }
         bool Attack(Unit* victim, bool meleeAttack);