Arthur Masuaku's late winner gave West Ham a 3-2 win over Chelsea, inflicting a second league defeat on the Blues.
Chelsea took the lead just before the half-hour mark through Thiago Silva's header, before a bizarre and uncharacteristic error from goalkeeper Edouard Mendy led to him fouling Jarrod Bowen after miss-controlling a back-pass.
Manuel Lanzini dispatched the penalty to level things up, but Chelsea re-took the lead just before the break thanks to a sweeping attacking move that ended with a sumptuous first time volley from Mason Mount.
Bowen levelled things up 10 minutes into the second half with a long-range strike, before the a dipping cross from Masuaku found it's way past Mendy to give the Hammers a 3-2 lead with just three minutes left of the 90.
Not only did the Hammers limit Chelsea impressively in the second half to chances equating to 0.50 xG, but over the course of the game they became just the third team across the Premier League and Champions League to rack up 2+ xG against Chelsea this season.
The win means David Moyes's side create a four point cushion in fourth and move within six of leaders Chelsea, who could lose their grip on top spot this weekend with Liverpool and Manchester City yet to play.
