The decisive moment came from a catastrophic miss by Edinson Cavani in the dying seconds of the match.
The first leg ended with a narrow 1-0 victory for the Peruvians. In the return fixture, Boca Juniors quickly took the lead thanks to an own goal from Miguel Trauco in the 5th minute.
However, Alianza Lima equalized before halftime, but early in the second half, Argentinians took the lead, making it 2-1. With no further goals from either team, the match proceeded to extra time.
In the dying minutes of regular time, Edinson Cavani had a golden opportunity to put his team ahead but failed to hit the target from a favorable position. This miss proved fatal for Boca, as Alianza Lima prevailed in the penalty shootout.
As a result, Boca failed to advance to the group stage of the Copa Libertadores, and Cavani became the unlikely villain of the match.