Goals from Alejandro Balde, Jules Kounde and a brace from Robert Lewandowski were enough for Barca to see off their relegation-threatened inner-city rivals.
Inside the opening five minutes Pedri really should've bagged the decisive goal for his side. After being found by a clever pull-back cross by Jules Kounde, the unmarked Spanish international swept his subsequent effort wide of the foot of the post.
They didn't have to rue that miss for too long however as, in the 11th minute, Barca hit the front thanks to Robert Lewandowski. The Polish striker rushed in at the back post to tap home an Alejandro Balde cross from the left to give his side a crucial lead.
Just eight minutes later, Balde went from creator to goalscorer, bagging Barcelona's second goal of the game. The left-back stole in at the back post to volley home a lovely dinked cross from Pedri.
Barca's dominated the remainder of the first half with relative ease, and deservedly added a third goal in the 40th minute. The third would be scored by Lewa (who else?), who tapped home a lovely drilled cross along the six-yard box from Raphinha to make Barca's already unassailable lead even more unassailable.
Soon after the start of the second half it was 4-0 to Barca, with Jules Kounde stealing in behind Javier Puado to head home a delightful Frenkie de Jong cross.
After going four down, Espanyol finally showed a tiny bit of fight. That 'tiny bit of fight' culminated in Joselu being played through on goal on the right of the penalty area, but seeing his subsequent effort on goal well saved by Marc-Andre ter Stegen.
With Barca well and truly in first gear, Espanyol did manage to find the back of the net in the 72nd minute to make it 4-1. The goal would be scored by substitute Puado, who raced in behind the Barca defence before dinking the ball over the Barca keeper and into the net.
Amazingly Espanyol would bag as a second with the final kick of the game, as Joselu tapped in from three-yards out to make the scoreline a bit more respectable.
Source: 90min.com