Antoine Griezmann took full advantage of shoddy Arsenal defending to earn a draw for Atletico Madrid in their Europa League semi-final first leg.
Atleti defender Sime Vrsaljko was dismissed for two yellow cards in the ninth minute and after a spell of heavy pressure, Alexandre Lacazette gave the hosts the lead on the hour mark.
The French striker nodded in Jack Wilshere's cross just after the hour to apparently edge the Gunners closer to a Europa League final, while visiting boss Diego Simeone had long since been sent to the stands.
However, with eight minutes remaining, Griezmann latched on to a long ball forward, shrugged off Laurent Koscielny and stabbed into the net at the second attempt for an away goal.
Atleti have not conceded a goal in their last 11 home matches in all competitions and have yielded just four goals at home in 17 La Liga games.