Arsenal had a tense night on Thursday, losing 1-0 to Greek side Olympiakos but advancing to the Europa League quarter-finals 3-2 on aggregate.
Arsenal seemed at ease after a 3-1 win in Athens last week and hitting halftime unscathed in the return.
However, Youssef El Arabi’s deflected shot caught Bernd Leno off guard early in the second half, giving the visitors hope and increasing friction among the home players.
Arsenal squandered many late opportunities to relax nerves, with captain Pierre-Emerick Aubameyang, who was recalled to the starting lineup after missing Sunday’s north London derby due to administrative reasons, guilty of a bad miss.
Olympiakos’ Ousseynou Ba was sent off late in the game, and Arsenal avoided some late drama as it avenged last season’s elimination by the Greek champion to advance to Friday’s last-eight draw.