Tomas Soucek found an injury-time winner for West Ham at Burnley.
The Clarets were left floored as Vincent Kompany's side conceded two goals in five minutes late on.
Burnley had the lead via a Jay Rodriguez penalty on 49 minutes.
But West Ham equalised on 86 minutes through an own goal from Dara O'Shea under pressure from Hammers youngster Divin Mubama.
Then Soucek headed home five minutes later to leave the home support shattered.