Espanyol built on their 2-2 draw away to Villarreal in the first leg as they beat the Yellow Submarine 3-1 at the RCDE Stadium on Thursday night, with two penalties giving Rubi's side a perfect start.
Just after half an hour into the match, Borja Iglesias, celebrating his birthday, was brought down by Pepe Castano and Pablo Piatti stepped up to put the ball into the bottom left corner of Andres Fernandez's net as Espanyol took a 1-0 lead.
Just two minutes after scoring, the home side had another penalty.
This time, promising forward Javi Puado was fouled by Miguel Layun, and Iglesias - nicknamed 'the panda' - put his penalty into the same location as Piatti: the bottom left corner.
The drama in the first half did not stop there, however, as Villarreal were able to make it 2-1 through Samuel Chukwueze as his left-footed shot from the right side of the box beat Roberto Jimenez.
Qualification to the next round was sealed by Iglesias as he got his second of the night, following Didac Vila's header which set him up to score from close range.
It was not a perfect night for Espanyol, though, as they picked up two injuries on the night with Adria Pedrosa and David Lopez both having to come off, so Didac and Lluis Lopez came on respectively.
The match finished 3-1, meaning that the Catalan side are through to the last eight after winning 5-3 on aggregate.