Luis Enrique's side have now won their last five Liga home games in a row with Luis Suarez, Lionel Messi and Neymar all on target
Barcelona maintained momentum in the title race in La Liga, hammering Sporting Gijon 6-1 at Camp Nou on Wednesday.
Playing a couple of hours before Real Madrid took on Las Palmas, Luis Enrique's side proved far too strong against his hometown club to move top of the standings, at least momentarily.
Lionel Messi and Luis Suarez netted either side of a Juan Rodriguez own-goal, although Barca's recent dalliance with a confusing set up at the back led to a disjointed defensive display, which opened up space for Carlos Castro to score.