Arsenal slipped a late goal to hand Atletico Madrid the advantage in their Europa League semifinal on Thursday night.
The visitors were on the back foot for almost the entire game after defender Sime Vrsaljko was dismissed for two yellow cards in the first 10 minutes.
With Atletico's furious manager Diego Simeone sent to the stands shortly afterwards, the Spanish side survived unscathed to half-time with Alexandre Lacazette clipping the post with a half-volley in the hosts' best chance.
Lacazette nodded in Jack Wilshere's cross just after the hour to apparently edge the Gunners closer to a Europa League final send-off for outgoing manager Arsene Wenger.
But with eight minutes remaining Antoine Griezmann latched onto a long ball forward, shrugged off Laurent Koscielny and stabbed into the net at the second attempt to swing the tie Atletico's way.
Afterwards, Gunners striker Danny Welbeck said, "It's disappointing to concede a goal at the end after taking the lead. We will do our own analysis on their goal and make sure it doesn't happen again.
"This game is done now and there were opportunities for us to score more against a good side, so we have to be positive going into the second leg.
"It's a semi-final - we wanted to win before the manager announced he was leaving and we wanted to win it after. We are professionals but seeing him lift the trophy would be the icing on the cake."