Arsenal will have to forget that Atletico Madrid have conceded just four goals at home in La Liga this season.
The Gunners must score at the Wanda Metropolitano next Thursday after a 1-1 draw in the first leg of their Europa League semi-final tie in north London.
Atletico Madrid were down to 10 men after just 10 minutes and things got even better for Arsenal when Alexandre Lacazette gave them the lead in the second half.
Diego Simeone, who himself was sent to the stands, appeared content with a 1-0 defeat. Gabi was introduced in the 65th minute and Stefan Savic came on shortly afterwards.
But Atletico managed to grab a goal out of nowhere, Antoine Griezmann capitalising on some woeful defending to equalise in the 82nd minute, and the Spanish outfit are now favourites to advance to the final.
“We can only look at ourselves on tonight’s result,” Arsene Wenger said afterwards.
“1-0 is a perfect result at home. It was down to us just not to make a mistake.”
Wenger put his trust in David Ospina and the goalkeeper will be disappointed with the manner of Griezmann’s goal.
But Ospina did show another positive with a quite immaculate pass to Aaron Ramsey in the first half.
Ospina’s pass left football fans on Twitter stunned.
“Haven't seen anything of that nature from a keeper,” wrote @91sticker on Twitter.
One fan even compared it to Xabi Alonso…
Ultimately, though, Arsenal and their fans were left disappointed at a wasted opportunity to establish a lead heading into the return fixture.
“Of course, you come out tonight with a bitter taste because we had the chances to be in the final tonight,” Wenger, who will leave Arsenal at the end of the season, added.
“That’s where the regret is and we were not clinical enough.
“Unfortunately we gave a goal away, which puts us in a very difficult position.
“We need to rebuild the desire and confidence to go there and qualify.”