Ivan Toney’s 15th goal of the season salvaged a 1-1 draw for Brentford to prevent Arsenal from going eight points clear at the top of the Premier League.
Leandro Trossard’s first goal for the Gunners put them in front in the second half at Emirates Stadium on Saturday, but the prolific Toney levelled with a header after 74 minutes of the London derby.
Toney also struck the crossbar in the first half before he was an awarded the equaliser following a VAR check as the impressive Bees deservedly extended their unbeaten run to 10 top-flight games.
Arsenal are now six points clear of second-placed Manchester City, who they play on Wednesday, but that is three games without a win for the leaders in all competitions.
Rico Henry wasted a glorious early chance to put Brentford in front when he failed to hit the target from close range after Toney picked him out.
The dangerous Toney was proving to be a real handful and the striker rattled the crossbar with a right-footed strike after combining superbly with Bryan Mbeumo.
Arsenal were struggling to break a well organised Brentford side down and Gabriel Martinelli fired a volley over the crossbar from inside the box when an opportunity came the Brazil winger’s way late in the first half.
David Raya denied Buyako Saka at his near post and Martin Odegaard shot straight at the Bees goalkeeper in a bright start to the second half.
Brentford continued to pose a threat and Toney side-footed just wide when he was presented with another good opportunity to open the scoring.
It was Trossard who got the breakthrough four minutes after replacing Martinelli, stealing in to turn in Saka’s fizzed cross from inside the six-yard box to raise the roof.
Arsenal’s joy was short-lived, though, as Toney nodded into an empty net after Christian Norgaard set him up, the Gunners paying the price for being unable to deal with a set-piece as the goal was allowed to stand following a check for offside.