Pep Guardiola's side struggled to prise open Brentford for almost an hour at the Etihad Stadium.

But Doku's latest dazzling strike broke the deadlock before Erling Haaland bagged his 26th league goal this season.

Omar Marmoush wrapped up an essential City victory in stoppage-time.

City closed to two points behind leaders Arsenal, putting pressure back on Mikel Arteta's team to win at third-bottom West Ham on Sunday.

After their damaging 3-3 draw at Everton on Monday put the destiny of the title in Arsenal's hands, City did their bit to prolong the drama.

City will have a game in hand on Arsenal after this weekend, but the Gunners are guaranteed to clinch the title for the first time in 22 years if they win their remaining matches against West Ham, Burnley and Crystal Palace.

Guardiola's men host Palace on Wednesday before turning their attention to the FA Cup final against Chelsea on May 16.

Foreshadowing his match-winning contribution, City winger Doku forced an early save from Caoimhin Kelleher.

But  Gianluigi Donnarumma almost gifted Brentford a goal when Michael Kayode's long throw was scrambled off the line after the City keeper made a hash of his attempt to catch the ball.

Donnarumma's lackadaisical effort was in keeping with City's laboured attempts to take control.

Haaland wastefully headed high and wide when Doku's cross picked out the striker just six yards from goal.

When Haaland met Doku's cutback with a close-range blast, Kelleher repelled it before Nathan Ake failed to convert the rebound to groans from City's frustrated fans.

Bernardo Silva escaped with a booking after the City midfielder lashed out at Nathan Collins.

City were equally lethargic at the start of the second half and Donnarumma had to save Igor Thiago's low drive.

Guardiola sent on Marmoush and Phil Foden in a bid to spark City into life and the move paid instant dividends.

Doku had scored twice with a eye-catching curlers against Everton and he repeated the trick to end Brentford's resistance in the 60th minute.

Seizing the rebound after his initial effort was blocked, Doku whipped a superb strike into the top corner from the left-hand side of the penalty area.

Doku's fourth goal in his last three games was nearly followed by one for Foden, but Kelleher was equal to his close-range shot.

City were still vulnerable at the back and Kevin Schade appealed in vain for a penalty after contact from Matheus Nunes.

Haaland settled City's fraying nerves in the 75th minute, back-heeling in from close-range after his first effort was blocked from Antoine Semenyo's cross.

Marmoush bolstered City's goal difference, which is now just one less than Arsenal's, with a composed finish from inside the area in the final seconds.

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