Chelsea made it back-to-back defeats in the Premier League and three games without a win as they suffered a 1-0 home defeat to West Ham on Saturday, November 30.
The Blues started brightly as Christian Pulisic header in the 10th minute just sailed over the bar before Reece James cross hit the woodwork in the 22nd minute.
They could have taken the lead in the 43rd minute but a brilliant double save from David Martin denied Kovacic and Giroud from close range.
But despite a strong start to the game, the Blues went behind just three minute into the second half as Aaron Cresswell found space inside the boxer to curl a beauty into the net.
West Ham thought they had scored their second as Michail Antonio bundled home after a mix-up in the Chelsea backline. But replay showed the ball touched his hand on its way into the net, leaving VAR to rule out the strike.
Chasing the game, Frank Lampard made a double change as Willian came on for Pedro while Kante was introduced for Jorginho.
Shortly after, Hudson-Odoi was introduced into the game as he came on for Oliver Giroud but Chelsea were far from their best and didn’t look like getting something out of the game.
West Ham held on to claim vital three points as manager Manuel Pellegrini secured an important away win to save his job.
The defeat also meant that Chelsea suffered back-to-back defeat in the Premier League for the first time since January.
It was also West Ham’s first victory at Stamford Bridge in 14 visits dating back to 2002.