Italian leaders Napoli suffered a surprise 3-1 home defeat at the hands of RB Leipzig as Timo Werner scored twice.
Things seemed to be going the hosts' why when Adam Ounas opened the scoring seven minutes after half-time, but Werner slotted home to equalise nine minutes later.
Bruma then put the German club ahead on 74 minutes after beating an offside trap, and with Napoli pushing for an equaliser, it was the visitors who found the final goal on a counter-attack, Werner finishing at the near post.
Atletico Madrid took a commanding advantage in their first leg with a 4-1 victory at FC Copenhagen.
The hosts took a shocking lead after 15 minutes when Viktor Fischer back-heeled home from close range after a powerful Peter Ankersen effort toward goal.
But Diego Simeone's side stormed back with unanswered goals from Saul Niguez, Kevin Gameiro, Antoine Griezmann and Vitolo to all but seal their place in the last-16 ahead of next week's return match in Madrid.