David de Gea's howler allowed Arsenal to score their opener in the 2-2 draw against Manchester United on Wednesday.
De Gea, who has kept just two clean sheets in 15 games for United in the Premier League this season, let a Shkodran Mustafi header slip through his fingers in the first half, with Matteo Darmian unable to keep the ball off the line.
That put Arsenal ahead, before Anthony Martial equalised just minutes later. Marcos Rojo's own goal then put Arsenal ahead again in the second half, only for Jesse Lingard to net just 13 seconds after the restart to secure a draw.
Watch the howler in the video above