Hammers who have been brilliant this season are now 27 points in 15 matches and just 4 points behind third place Liverpool.
Thiago Silva had set the stadium buzzing with his early goal scored at 28th minutes, unfortunately for the Blues Westham recuperated immediately to level up when Mendy could not clear out a dangerous back pass from Jorginho leading to a foul from Mendy on Bowen. Lanzini converted from the spot kick to make it 1-1.
Mount set ahead Chelsea at 44th minutes, Bowen level up at 56 Minutes. And at 87 minutes Athur Masuaku seal the winner from Hammers scoring what seems like goal of the week.
Only Manchester United have won an EPL tie this season at westham with Manchester City, Liverpool, Leicester, Totteham and Chelsea all have failed to grind a win at westham.
Manchester City and Liverpool will go ahead of Chelsea should they win this evening.