Munir El Haddadi scored both goals as Barcelona beat Espanyol 2-0 on Wednesday to ease into the Copa del Rey's quarterfinals with a 6-1 victory on aggregate.

Two days after collecting his record fifth Ballon d'Or award, Lionel Messi played El Haddadi through with a long pass to score Barcelona's opener in the 32nd minute.

The 20-year-old El Haddadi netted his second with two minutes left.

"This is good for Munir, the fact that he participated in many facets today," coach Luis Enrique said about the little-used forward. "He has a knack for scoring."

After two ill-tempered derbies in the past two weeks- a 0-0 draw in the Spanish league before Barcelona'a 4-1 first-leg win that featured 20 yellow cards and two reds- the return match at RCDE Stadium was a tame affair, only brought to life by Messi.

"Today we saw a much calmer match, perhaps in part because the result was difficult to overcome, but this has been talked about too much," Luis Enrique said.

Villarreal crashed out of the competition after being beaten 1-0 at home by Athletic Bilbao.

The Yellow Submarine squandered a two-goal lead to lose 3-2 to last year's beaten finalists in the first meeting and they were unable to overcome the deficit on home soil.

Bilbao forward Inaki Williams shrugged off a tackle before breaking the deadlock in the first period with his 10th goal of the season to make it 4-2 overall.

Former Manchester City striker John Guidetti converted a first-half penalty as Celta Vigo saw off Cadiz to progress.

Celta, 3-0 winners in the first leg, won 2-0 on the night thanks to goals from Guidetti and Dejan Drazic.

Las Palmas are also through thanks to another 3-2 victory over La Liga's surprise package Eibar.

In the first leg, Figueroa Momo's 90th-minute goal had given Las Palmas an away win after two Eibar players were sent off and they were on course for the next round when David Junca's own goal put them ahead in the second leg.

Two goals in as many minutes from Borja Ekiza and Sergi Enrich levelled it up at 4-4 on aggregate, though, before first-leg hero Momo and David Garcia scored to send Las Palmas through.

Lionel Messi (C) tries to score past Espanyol's Spanish goalkeeper Pau Lopez during the Spanish Copa del Rey (King's Cup) round of 16 first leg football match on January 6, 2016. Photo: AFP