Arsenal’s eight-game Champions League winning streak ended after substitute Kai Havertz scored an 89th-minute penalty to earn a 1-1 draw at Bayer Leverkusen.
Havertz, a former Leverkusen player, converted the late spot kick to cancel Robert Andrich’s 46th-minute header, the first time Arsenal trailed this season in Europe’s elite competition.
Both teams will meet again on Tuesday in London for the return leg and a place in the Champions League quarter-finals.
Arsenal coach Mikel Arteta said his side controlled the game but failed to score.
“Then we let the game slip away. That was unnecessary. We gave them hope and it became a different game,” Arteta said.
Arteta added that Arsenal improved in the final 20 minutes and deserved the equaliser.
The Premier League leaders, who won their previous eight matches, started brightly with Gabriel Martinelli striking the crossbar with a powerful effort in the 19th minute.
Leverkusen absorbed the pressure and gradually settled, with Christian Kofane’s runs posing problems for the Arsenal defence.
The hosts struck immediately after the restart when Alex Grimaldo delivered a corner to the far post for an unmarked Andrich to head home.
Arsenal struggled to respond as Arteta replaced Bukayo Saka with Noni Madueke after an hour and later introduced Havertz to loud applause from the home crowd.
Jurrien Timber missed a clear chance in the 85th minute, heading over the bar before Madueke went down in the box after contact with Malik Tillman.
Following a lengthy VAR review, Havertz calmly converted the penalty to secure the draw ahead of next week’s return leg in London.
Havertz said the wait before taking the penalty felt long but he stayed mentally focused.
He noted familiarity with the stadium and previous penalty experience there boosted his confidence, adding that Arsenal now face another big task in the second leg.
