Lionel Messi and Luis Suarez both scored as Barcelona……
Suarez turned in the opener for the visitors from Aleix Vidal’s drilled cross, before Neymar tapped in the second from close range.
Barca turned on the style in the second half with four goals in the space of nine minutes, as Messi stroked in the third before Alexis’ own goal.
Ivan Rakitic smashed home from inside the area and Suarez added the sixth.
These two sides will meet again on Saturday, 27 May in the final of the Copa del Rey after Barca got past Atletico Madrid and Alaves edged through against Celta Vigo.
The visitors dominated this match and fully deserved their win with 70% possession, as well as scoring with six of their nine shots on target.
Uruguay forward Suarez was on the scoresheet again and now has 18 goals this season, making him the league’s top marksman, one ahead of team-mate Messi.
Real Madrid picked up a 3-1 victory over Osasuna to propel themselves back to the top of La Liga.
Cristiano Ronaldo’s opening goal was cancelled out by Sergio Leon, but in the second half Isco gave Zinedine Zidane’s side the win before Lucas Vazquez got a third in stoppage time.