Chelsea's poor run under Graham Potter continued as Manchester City cruised to an emphatic 4-0 victory in the FA Cup third round.

Three days on from going down 1-0 to City in the Premier League at Stamford Bridge, Chelsea capitulated at the Etihad Stadium.

Riyad Mahrez's stunning free-kick, Julian Alvarez's penalty and Phil Foden's close-range finish had City all but through by half-time on Sunday.

A late Mahrez spot-kick provided the fourth as City look forward to a possible fourth-round meeting with league leaders Arsenal – who must defeat Oxford United to make that tie – while Chelsea showed little sign that immediate improvement under Potter is on the horizon.

Cole Palmer should have done better early on, but City did not have to wait long for their lead – Mahrez curling a brilliant free-kick into the top-right corner after being fouled by Lewis Hall 25 yards from goal.

Kai Havertz's desperate handball gifted City a chance for a second following a VAR check, and World Cup winner Alvarez's penalty snuck in under Kepa Arrizabalaga.

Mahrez was key to an exceptional third goal to put the tie to bed, sliding a perfectly weighted pass through to Kyle Walker, whose cutback was expertly turned home by Foden.

Chelsea had their first shot in the 55th minute, but Stefan Ortega was hardly troubled by Mason Mount's effort.

At the other end, Chelsea could not avoid further damage as Kalidou Koulibaly clattered into Foden late on.

Mahrez made no mistake from the spot, slamming high down the middle to cap a superb win and a miserable day for Chelsea, who exited in the third round for the first time since the 1997-98 season.