Havertz struck at the far post to convert Bukayo Saka’s cross and lift Arsenal back to the top for the first time since May 2.
Kai Havertz climbed off the bench to fire Arsenal to the top of the Premier League with a late winner to sink Brentford 1-0.
Manchester City’s 1-1 draw with Liverpool at lunchtime left the door open for the Gunners to hit the summit for the first time since May 2.
They did not look like doing so for 89 minutes against a stubborn Brentford side, and at times were grateful the hosts did not punish some rudimentary errors from goalkeeper Aaron Ramsdale.
But 10 minutes after coming off the bench, Havertz struck at the far post to convert Bukayo Saka’s cross and lift Arsenal back to the top for the first time since last season’s title bid fizzled out.
Ramsdale was back in the spotlight on his first Premier League appearance since September 3 with David Raya, now seemingly the club’s undisputed number one, still on loan from Brentford and ineligible to face his parent club.
The England keeper made a nervous start with a shanked clearance into touch, and, with his every move mocked by the Bees fans, then proceeded to almost gift Brentford an early goal.
Having exchanged passes with Gabriel from a goal kick, Ramsdale suddenly developed a bout of the yips, hesitating with his clearance and allowing Yoane Wissa to pinch the ball away.
Luckily for Ramsdale, Declan Rice had already spotted the danger and got back to clear Bryan Mbeumo’s shot off the line, before Wissa put the rebound wide.
But Ramsdale hid his face under his shirt following another embarrassing error before half-time, somehow letting the ball slip out of his hand.
Instead of throwing it up-field he ended up looking like a fast bowler delivering a bouncer which went straight to Bees midfielder Frank Onyeka. The danger was quickly cleared, however.
The Gunners were faring little better at the other end with striker Gabriel Jesus, making his first Premier League appearance in a month, heading into the side-netting and blazing a shot over.
They did get the ball in the net just before half-time thanks to more inauspicious goalkeeping, this time from Mark Flekken, who palmed a Jesus header into the air, allowing Leandro Trossard to bundle it home, but VAR ruled the Belgian was offside.
Mikel Arteta, who launched his recent VAR rant after his side were beaten by a goal scored from a very similar position by Newcastle, looked on impassively from the touchline.
Brentford had chances after the break, with Mbeumo firing off target, Yehor Yarmoliuk shooting straight at Ramsdale and substitute Neal Maupay prodding wide from close range.
But the Gunners won it when Saka swung in a cross from the right and Havertz ghosted in at the far post to plant his header past Flekken and send them back to the top of the pile.