West Ham missed the chance to go top of the Championship table as Burnley came from behind to win at Upton Park.
The Hammers went ahead through Kevin Nolan's effort from the edge of the area but the lead lasted just five minutes when Chris McCann headed home from close range.
The visitors then wrapped up the win when Sam Vokes, on loan from Wolves, headed in Ross Wallace's corner.
The Clarets have now won three in a row and have climbed to 10th spot.
The Hammers remain in second place, with a trip to Reading up next for Sam Allardyce's men.
West Ham dominated the opening period with Matt Taylor heading Julien Faubert's cross over the top before Nolan missed another chance from eight yards out.
After the break, Frederic Piquionne headed Faubert's cross straight at Lee Grant before a shot from Jack Collison was blocked in front of goal.
Meanwhile, Wallace went close to adding another for Burnley with an effort that rolled fractionally wide.