Alberto Saiz/Associated Press
Anzhi Makhachkala 0-0 AZ Alkmaar
Dutch side AZ Alkmaar advanced to the quarter-finals following a scoreless draw in Russia. AZ won 1-0 last week in Holland.
Valencia 1-0 Ludogorets Razgrad
Paco Alcacer headed in the only goal in the 59th minute as Valencia cruised into the quarter-finals with a 4-0 aggregate victory.
Viktoria Plzen 2-1 Lyon
Bafetimbi Gomis scored in the first half before Plzen pulled two goals back in the second half, through Daniel Kolar and Stanislav Tecl, to make it 5-3 on aggregate.
Tecl also missed a penalty for the hosts.
Real Betis 0-2 Sevilla (a.e.t.)
Jose Antonio Reyes and Carlos Bacca scored either side of half-time as Sevilla erased a 2-0 deficit from the first leg.
After 30 scoreless minutes of extra time, Sevilla won the penalty shootout 4-3.
SV Salzburg 1-2 FC Basel
Jonathan put Salzburg ahead in the 22nd minute, but Basel fought back with second-half goals from Valentin Stocker (51') and Gaston Sauro (59').
Basel had Marek Suchy sent off in just the ninth minute. The Swiss side advanced 2-1 on aggregate following a scoreless draw in the first leg.
The match was delayed briefly in the first half, per Yahoo! Sports, after Basel fans threw objects onto the pitch following Salzburg's opening goal.