Alexis Sanchez put his off-field problems aside to help Arsenal kick off their Europa League Group H campaign with a 3-1 over Cologne following a one-hour delay due to crowd congestion.
Sanchez has cut a frustrated figure this season having seen a reported move to Manchester City fall through, but his moment of quality proved decisive on a bizarre Thursday night at the Emirates Stadium.
The game began amid swirling controversy, having been put back 60 minutes after a reported 20,000 Cologne fans descended on London despite only 3,000 tickets being available.
It appeared several were also in the Arsenal end, and they were quickly sent into raptures when Jhon Cordoba opened the scoring with a stunning 40-yard strike after nine minutes.
A lifeless atmosphere among the home contingent, depleted in numbers presumably because some fans opted to return home, was invigorated after the break as substitute Sead Kolasinac levelled.
And Arsenal ultimately condemned Cologne to defeat in their first European outing for 25 years thanks to Sanchez and Hector Bellerin's first goal of the campaign.