In the first leg, for the second season in a row, the Gunners lost 5-1 in Munich having gone down by the same scoreline in the 2015/16 group stage. Thiago Alcántara scored twice and Arjen Robben, Robert Lewandowski and Thomas Müller all found the net as Bayern inflicted the Gunners' joint heaviest European defeat.
Only three clubs have managed to recover a four-goal first-leg deficit in UEFA competition. VfL Borussia Mönchengladbach beat Real Madrid CF 5-1 at home in the 1985/86 UEFA Cup third round, only to lose the return 4-0.
