Kai Havertz, entering from the bench, saved Arsenal as their flawless Champions League record concluded in Leverkusen.
Throughout the match, the Gunners appeared uninspired, experiencing a taste of their own tactics when they conceded from a curling corner kick early in the second period.
Yet, following Noni Madueke’s penetrating surge that earned an 89th-minute penalty, Havertz, a fellow replacement, advanced to dispatch it.
The German international refrained from celebrating against his former club, which he represented for a decade prior to his move to Chelsea. Nonetheless, his strike could still prove decisive in this fixture.
Gabriel Martinelli rattled the crossbar following a superb counter-attack, marking Arsenal’s most effective offensive play. Yet, they could only muster two attempts on target throughout the evening, with Leverkusen confining them to just three corner kicks.
The host team’s confidence surged, and they went ahead at the commencement of the second period.
Martin Terrier was repelled by David Raya a mere 10 seconds post-restart, but from the subsequent corner, Robert Andrich nodded in with force.
Andrich was arguably fortunate to have remained on the field, receiving a caution in the opening seconds for fouling Viktor Gyokeres after the Sweden international had skillfully evaded him on the edge of the penalty area.
A short while after, Andrich physically challenged Gyokeres near the touchline but avoided a second caution from official Halil Umut Meler.
Despite achieving an eight-game winning streak in the league phase, Arsenal were far from their optimal level and appeared set to prolong a dismal midweek for Premier League teams up to this point.
Madueke, however, ignited a spark, and following his foul by Malik Tillman, Havertz maintained his composure to convert a vital goal.
Arsenal or Leverkusen are slated to confront Bodo/Glimt or Sporting in the quarter-final stage.
The Champions League Fixture List
The pairings for the Champions League quarter-finals are:
Paris Saint-Germain or Chelsea v Galatasaray or Liverpool
Real Madrid or Manchester City v Atalanta or Bayern Munich
Newcastle or Barcelona v Atletico Madrid or Tottenham
Bodo/Glimt or Sporting CP v Bayer Leverkusen v Arsenal
The fixtures for the Champions League semi-finals are:
Silver path: PSG/Chelsea/Galatasaray/Liverpool v Real Madrid/Manchester City/Atalanta/Bayern Munich
Blue path: Newcastle/Barcelona/Atlético Madrid/Tottenham v Bodo/Sporting CP/Bayer Leverkusen/Arsenal