On 71 minutes, delight for Manchester City and heartbreak for Brentford. Thomas Frank’s ploy of defending with 10 and hoping for a breakaway strike had disrupted the champions who appeared bereft of ideas. But then came the hosts’ sheer quality in a lightning sequence that had Rúben Dias finding Rodri near their area. He passed to Julián Álvarez whose ball landed at the thus-far ineffective Erling Haaland. Not now, though, because as he raced in, Kristoffer Ajer slipped and the lethal 23-year-old beat Mark Flekken to the goalkeeper’s right from inside the D.

Game over, despite Flekken’s appearance in City’s area at a 95th-minute corner. Haaland’s winner, which means he has scored against all 21 Premier League teams he has faced, moves City to a point behind Liverpool and makes their trip to Anfield on 10 March a seismic clash that hands the victor total control of their destiny. Strap yourself in for that one.

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Haaland had been criticised for missing chances against Chelsea on Saturday. Pep Guardiola said: “If I have to choose one [to score in then] I choose this one. Top strikers score a lot of goals – don’t criticise, he will shut your mouth. Sooner or later he is there. He was out for two months, he lost his grandmother [last Saturday week], it is not easy for a human being.

“It is really difficult for us [against Brentford]. Last season we lost six points against them. In these type of games, you need Erling.”

After a heavy downpour for a second successive match the surface was suitably greasy for City to ping the ball about.

The Premier League hype machine made much of their two dropped points against Chelsea yet that draw made it nine unbeaten in the league, with Guardiola’s side the land’s best for the past three seasons at judging their run to the tape in late May. Now make it 10 unbeaten.

Guardiola opted for a lesser-seen 4-2-3-1 that had Bernardo Silva alongside Rodri and the two schemers joined the attack incessantly to crowd the zone around their visitors’ area and hassle them. As did Haaland when stomping up to Sergio Reguilón, dispossessing the defender, pivoting, and aiming a sighter that Flekken collected easily. Brentford’s keeper next flung himself at a corner to repel a Phil Foden rocket but this was blocked and Frank’s side escaped.

Chelsea had prospered, as so many do against City, via the slick counter so to see Frank Onyeka race clear down an inside-left channel was no surprise. Though the midfielder, latching on to Yoane Wissa’s pass, had to be more decisive than the feeble effort that was no problem for Ederson to clutch.

When Guardiola drops to his haunches it is a sign of stress and he adopted the position after Onyeka claimed a free-kick after Dias challenged. Reguilón touched the ball to Ivan Toney but the centre-forward’s effort sailed high. The latter is the proverbial nightmare package of strength, control, pace and guile for defenders; as John Stones discovered when he was backed into, barged aside, and had to watch helplessly as the ball was laid off.

City hogged almost 70% of the ball so Brentford were in siege mode. The dam nearly broke when Stones dropped a lob for a running Kyle Walker whose header found Silva but he spurned the chance from close range.

Dias, too, missed with his forehead from even nearer when Rodri picked him out at the far post, this following a Manuel Akanji 20-yard dipper tipped over by Flekken. Then Oscar Bobb showed the cool required in traffic to drop a shoulder and fire low and hard, Ben Mee’s goalline clearance drawing a hug from Flekken.

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All of this was frustrating for City whose mood would have darkened if an Onyeka header had beaten Ederson. On the bench Kevin De Bruyne waited to be called upon. Guardiola explained why he remained there. “Today we could not use Kevin because he had niggles in his hamstring and I didn’t want to take a risk. He is OK – it was just prevention but he didn’t feel comfortable and so after five months off [with a hamstring injury] we didn’t take any risk,” the manager said.

For the second half Guardiola removed his coat as if it was now down to the serious business of the quest for the victory that would move City on to Liverpool’s shoulder. Yet whatever he told his players at the break was not heeded as Brentford were able to make the contest bitty. More than once he bellowed at his charges. A fortnight ago a Foden hat-trick was too much for Brentford in the reverse fixture. This time City had descended to as close to chaotic as they can. A nadir arrived when Silva punted a free-kick sideways and straight out. Guardiola removed Bobb for Jérémy Doku in the hope his searing speed would be the X-factor. He chipped to Haaland but the Norwegian’s arm hit Mee, Darren England blew, and City were stymied once more.

But Haaland’s 17th league goal of this season transformed City’s night into joy. In the red half of Merseyside, the emotion is the opposite while Frank found a silver lining in defeat, saying: “Our performance gives me hope for the future.”