Arsenal had eight straight wins and a superior first place when the regular season was summed up in the Champions League. But in the round of 16 away against Leverkusen, Arsenal had a tougher time.
The home side started the second half in blazing fashion. Leverkusen's first real chance, Martin Terrier's header, led to a corner, and centre-back Robert Andrich crept to the far post and headed the opener behind goalkeeper David Raya in the 46th minute.
Andrich's direct hit looked like it would be enough for victory.
But Leverkusen's Malik Tillman drew a penalty in the duel with Noni Madueke - and substitute Kai Havertz, the German who previously played for Leverkusen, equalized in the 89th minute.
The return leg will be played in London on March 17.
Viktor Gyökeres, Arsenal's Swedish forward, played from the start and was substituted after 74 minutes.
