Levante 2-1 FC Barcelona
Philippe Coutinho gave FC Barcelona some hope by netting a late away goal in their 2-1 defeat Levante in the first leg.
The visitors opted to rest Lionel Messi, Luis Suarez and Marc-Andre Ter Stegen for the first leg.
The hosts raced into a fourth-minute lead after Erick Cabaco headed past Jasper Cillessen, before the lead was doubled thanks to Borja Mayoral's strike in the 20th minute.
Barca were awarded a penalty in the 85th minute after Denis Suarez was fouled in the box, which allowed Coutinho slot home from 12-yards out for an away goal.
Athletic Bilbao 1-3 Sevilla
Sevilla will take a commanding lead into the second leg on home soil after they defeated Athletic Bilbao 3-1 at San Mames.
Nolito gave the visitors the lead after six minutes, before San Jose restored parity after 49 minutes.
However, Sevilla hit back through Andre Silva in the 53rd minute while Wissam Ben Yedder netted the third with 13 minutes remaining.
Real Betis 0-0 Real Sociedad
Real Betis and Real Sociedad will have it all to play for in the second leg following their goalless draw at the Estadio Benito Villamarín.