The Reds celebrated an FA Cup triumph on Sunday (AEST) and their chances of an unprecedented quadruple looked very much alive after Jarrod Bowen's double put West Ham 2-0 up at the break.

Yet Jack Grealish pulled one back for City who, despite more shaky defending, drew level when Vladimir Coufal headed into his own goal.

The stage looked set for Mahrez to seal a brilliant comeback win when Craig Dawson's foul on Gabriel Jesus was spotted by VAR, but Lukasz Fabianski made a strong save to keep Liverpool, who are four points back with a game in hand, in the title hunt.

City had control of possession early on but West Ham were dangerous on the counter and that tactic paid dividends in the 24th minute when Bowen beat the offside trap, rounded Ederson and coolly squeezed home.

A shocked City initially struggled to respond, though Jesus' dipping shot almost found the bottom-left corner in the 36th minute.

Yet West Ham struck again before the interval – Bowen engineering space on the edge of the box and drilling a crisp finish beyond Ederson.

City's response came inside four minutes of the restart, Grealish's volley deflecting in off Dawson.

Grealish brilliantly teed up a chance for Bernardo Silva that drew a superb stop from Fabianski, though shambolic defending might have cost City had Bowen or Michail Antonio being more clinical.

West Ham was made to pay with 21 minutes left – Coufal heading Mahrez's free-kick beyond Fabianski.

Aymeric Laporte diverted a goal-bound Bowen shot wide before City were awarded a golden opportunity to win it when Dawson brought down Jesus.

Mahrez stepped up but Fabianski guessed the right way, much to Pep Guardiola's frustration.