Kai Havertz came off the bench to score an 89th-minute winner that sent Arsenal top of the Premier League with a 1-0 victory at Brentford.
Arsenal go a point above Manchester City and two clear of Liverpool, taking advantage of the two teams dropping points against each other earlier in the day.
How the match unfolded
Brentford were missing some key players, with Mathias Jensen, Mads Roerslev and Nathan Collins all picking up injuries during the international break, joining Rico Henry, Mikkel Damsgaard and Josh Dasilva on the sidelines.
Arsenal, in contrast, welcomed back Martin Odegaard and Gabriel Jesus, the latter making his first start since 21 October. Aaron Ramsdale also started in goal, with loanee David Raya ineligible to face his parent club.
Immediately, Brentford sensed nervousness from Ramsdale, and put him under pressure at every opportunity. A minute after forcing him to kick long out of play, he got his feet in a tangle and was dispossessed by Yoane Wissa, who passed to Bryan Mbeumo, whose shot was cleared off the line by Declan Rice.
Ramsdale continued to look uncertain, making a mess of a throw, but still tried to play out from the back, and it was Arsenal who thought they had taken the lead just before half-time.
Bukayo Saka's cross was headed at goal by Gabriel Jesus, whose effort was pushed into the air by Mark Flekken, allowing Leandro Trossard an easy close-range finish into an empty net.
But following a VAR review, Trossard was found to have been offside.
Despite having only 34 per cent possession, Brentford carried arguably the greater goal threat of the two teams, with Mbeumo prodding wide on the break before substitute Neal Maupay's header from Mbeumo's cross was cleared off the line, this time by Oleksandr Zinchenko.
It was almost a fantastic introduction for Maupay, who was spotted doing some last-minute homework before entering the match.
Rice then saw a shot blocked behind by Frank Onyeka, while substitute Eddie Nketiah shot tamely at Flekken, wasting a 3v2 in Arsenal's favour.
But there was still time for another substitute to strike the telling blow.
After replacing Gabriel Martinelli, Havertz met Saka's cross at the back post to head low into the goal to give Mikel Arteta a perfect result in his 200th match as Arsenal manager.
It was a sucker punch for Brentford, who fell to just a second defeat in their last 11 home Premier League matches, and stay 11th, with 16 points.
Referee: Tim Robinson. Assistants: Eddie Smart, Nick Greenhalgh. Fourth official: Josh Smith. VAR: Michael Salisbury.Assistant VAR: Wade Smith.