Bayern Munich effectively guaranteed themselves a place in the Champions League quarter-finals after the Bundesliga title-holders romped to a second 5-1 thrashing over Arsenal in successive seasons.
Carlo Ancelotti's hosts led through Arjen Robben's early goal, before Alexis Sanchez levelled for a Gunners side that improved markedly as the first half progressed.
It was a different, sorry story for the visitors after the break, as a Thiago Alcantara brace, Robert Lewandowski's header and Thomas Muller's late strike earned Bayern a commanding lead going into the second leg at Emirates Stadium next month.
For Arsene Wenger and his team, who crumbled in familiar fashion when it mattered most, a seventh successive exit from the competition in the round of 16 now appears all but inevitable.
Bayern dominated possession from the outset, Arturo Vidal testing David Ospina for the first time with a strike from outside the area in the ninth minute.
Two minutes later, though, there was nothing the Colombian goalkeeper could do to deny Robben.
Found by Douglas Costa's cutback, the Dutchman performed the manoeuvre that has become his career trademark, drifting in from the right flank, advancing past Francis Coquelin and curling an inch-perfect finish with his left foot into the far top corner of the net.