Chelsea clinched a 2-1 comeback win against West Ham United in dramatic fashion as Kai Havertz scored an 88th-minute winner, with a late equaliser from Maxwel Cornet ruled out by VAR.

Cornet smashed home after a mix-up at the back for Chelsea, but the goal was chalked off after Jarrod Bowen was deemed to have committed a foul in the build-up.

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That meant Thomas Tuchel's side secured a crucial victory to halt their indifferent start to the season.

Tuchel handed a Chelsea debut to Wesley Fofana after the defender's move from Leicester City while Mason Mount and Havertz were among the players dropped from the starting lineup after the shock defeat to Southampton in midweek.

Both sides made a slow start and the first genuine chance came in the 27th minute when Christian Pulisic had a shot blocked by West Ham's new signing Lucas Paqueta after a cross from Reece James was cleared out to the United States international.

The second half started more brightly, with Fofana trying his luck from range to no avail while Conor Gallagher halted Michail Antonio as the striker mounted a West Ham counter-attack.

Marc Cucurella was forced into a block from a Bowen effort in the 57th minute and the West Ham forward tested Mendy with a volley in the 62nd minute -- the game's first shot on target.

Mendy flapped at the resulting corner after it was flicked on by Paqueta, allowing Declan Rice to square for Antonio to slot home from close range.

Chelsea hauled themselves back into the game in the 76th minute when Ben Chilwell took advantage of a moment of madness from Lukasz Fabianski, poking through the keeper's legs after he hesitated following the left-back's flick-on from a long ball.

Substitute Havertz latched on to a cross from Chilwell to complete Chelsea's comeback with two minutes left of normal time, before Cornet responded almost instantly -- but Chelsea had the last laugh.