Record winners FC Sevilla, Atalanta Bergamo and FC Porto have reached the round of 16 in the Europa League.
Sevilla, second in Spain's La Liga, were able to afford a 0-1 (0-0) draw at Croatian champions Dinamo Zagreb in the second leg of the second round.
The Spaniards won the first leg 3-1.
After winning the first leg (2-1), the top Italian club from Bergamo celebrated an easy 3-0 (1-0) against Greek title holders Olympiakos Piraeus.
Things were tight for Porto: The Portuguese drew 2-2 (1-1) at Lazio Roma, having won the first leg 2-1.
Sevilla came under pressure again after a goal from Zagreb's Mislav Orsic (65', penalty kick), and former Dortmund player Thomas Delaney also saw yellow-red in the final stages (90' + 1').
The Croatians failed to score a second goal.
Danilo Cataldi (90+4) raised hopes again with the late equalizer for Lazio, but a goal was missing.
The most conspicuous man at Atalanta was the Ukrainian Ruslan Malinovskyi, who scored twice within four minutes (66th/69th).