Chelsea fail to secure a win against West Ham away from home; a win that will keep the Blue side 5 points ahead of rivals Manchester United.
The blue side were pushing for a draw with the game level (2-2) at the 88th minute, before a quick counter attack goal from Yarmolenko.
Willian scores penalty after Diop fouls Pulisic, Soucek header puts Hammers level
Antonio taps in for lead, Willian brings Chelsea level with free-kick, Yarmolenko for West Ham in 89th
Chelsea lose for the first time after the restart of the Premier League.
The blue side now prepare for Watford.