Arsenal fell to a narrow defeat at Cologne on Thursday night but will still progress into the knockout stages of the Europa League as Group H winners.
An uninspiring evening at the impressive RheinEnergieStadion saw the Bundesliga's bottom club secure a 1-0 win through Sehrou Guirassy's second-half penalty to keep their own qualification hopes alive.
On the back of a morale-boosting victory over north London neighbours Tottenham at the weekend, Arsene Wenger's second string could not maintain the feel-good factor for long.
Defeat here ended a perfect run in this competition so far this season but, following a draw between Red Star Belgrade and BATE Borisov in the group's other game, the Gunners will finish top.