After a biblical downpour, the skies cleared, and Manchester City executed the gameplan: secure victory and three points to keep their breath on Arsenal’s neck.

The clincher arrived via Erling Haaland’s 26th Premier League goal of the season – as with his side’s performance this was hardly pretty but no one in blue cared. Antoine Semenyo marauded down the right, his cross hit at least one Brentford body, the ball came to Haaland who, with a second stab at it, bundled home, the No 9 facing away from goal.

Pep Guardiola jumped into the arms of his assistant, Kolo Touré, and City could relax and tune into Arsenal’s trip on Sunday to West Ham praying they do them a favour.

Afterwards the manager took up this theme. “Come on you Irons”, he said, and playfully crossed his arms to ape the club’s badge, which shows two hammers.

The Catalan did so because the deficit is down to two points but each have played 35 matches so Arsenal cannot be caught if West Ham, Burnley and Crystal Palace are beaten. Yet though City struggled before the scintillating Jérémy Doku’s solo effort on the hour, they retain hope.

Once more they missed the control of Rodri, so played in flashes. One came when the menacing Doku muscled along the left and flipped the ball to Haaland: the big No 9 blazed at goal but a deflection, plus Caoimhín Kelleher’s hands, saved the visitors.

Brentford showed why only one of their previous eight games in the competition had been defeats, bringing a blend of competitiveness and pressing that caused City to unload from distance. Tijjani Reijnders (twice), Rayan Cherki, Doku and Bernardo Silva were all thwarted.

They also took the contest to them, primarily in a first-half passage. This featured Gianluigi Donnarumma flapping at a long throw, the ball bouncing off Matheus Nunes and on to Silva before Nunes hoofed clear. Then, Nunes passed straight to Mikkel Damsgaard and, as Guardiola watched dismayed, the Bees broke, but they lacked teeth.

Cherki joined the right-back in the clumsy stakes when a heavy touch caused him to foul Aaron Hickey: Mathias Jensen dropped the free-kick into City’s area and a diving Donnarumma pushed it away.

City’s stop-start mode followed the narrow 1-0 win at Burnley and Monday’s 3-3 draw at Everton and showed a loss of fluidity precisely when not required – in the defining phase of the championship race.

They carried the greater threat, though – usually through Doku, who continually pierced Hickey’s right-back corridor to shoot, or create: Nico O’Reilly, Silva, and Haaland were all found – the striker failed to finish, as he did with an earlier header that found Kelleher’s hands.

Guardiola had dropped a surprise by selecting Reijnders instead of Nico González. The midfielder’s previous league start was the 2-0 win over the bottom team, Wolves, on 24 January but of this Guardiola said: “I wanted runners to arrive in the area.”

When the sides changed ends, City had 45 minutes to break the deadlock. They nearly conceded when a slick Brentford free-kick routine began by Jensen closed with Kristoffer Ajer agonisingly near to slipping in behind. Then Igor Thiago, on 22 league goals to Haaland’s 25 (at this juncture), galloped forward and unloaded and required Donnarumma and Marc Guéhi to keep City intact.

City were entrenched in unfamiliar territory – their own – and so on 59 minutes Guardiola acted. Off came Reijnders for Phil Foden and Cherki for Omar Marmoush. It worked instantly as Brentford lost concentration. City had claimed a corner before the substitutions and, now, Silva took it from the left, short to Doku. The No 11 danced with the ball before hitting it in, playing an inadvertent one-two with Damsgaard. Now, as with his late equaliser at Everton, he cut inward and curved a peach beyond Kelleher that kissed the far left of the net. Cue a Guardiola jig and the ranks of City fans hitting ecstasy regarding a goal felt in the red zone of north London.

The Belgian dedicated his goal to his father, David. “It’s his birthday. I’m becoming a dad soon and he sacrificed his life for me not knowing I would be what I am now. That’s a big thing – him turning 60.”

Volume ratcheted and City were roared on, Foden going close to adding the second. Yet Brentford knifed through the home defence: Dango Outtara put Thiago in, he tapped to Kevin Schade, and the No 7 went to ground in the area under Nunes’s attentions.

Keith Andrews screamed for a penalty but the video assistant referee backed the referee, Michael Salisbury, in not awarding the spot-kick. Brentford’s manager said: “The comment I heard [from the officials] was not enough contact. For someone who is as quick as Kevin Schade, I don’t know how much contact it needs.”

Marmoush’s late third upped the goal difference which may prove vital.