Arsenal dropped points for the fifth time in seven Premier League games as they were held to a 1-1 draw by Brentford in Saturday's London derby at the Emirates.
The result left the Gunners 10 points behind leaders Liverpool with only 18 points left the play for.
Kieran Tierney had a goal disallowed by semi-automated VAR technology in the first half before Thomas Partey opened the scoring for real on 61 minutes.
Partey was later subbed off with an injury.
Yoane Wissa then equalised for Brentford with his 16th goal of the season.