Former Manchester United star Ronaldo struck a superb hat-trick in the rout.
"I'm happy with the three goals. The credit also goes to my colleagues. This is my year of adaptation and I'm happy to play well and to help the team," Ronaldo said afterwards.
"It's my first year here and I want to be champion. We know that Barca is good but we hope and want to win a title.
"The team got the result despite pressure from Barcelona. The team played very well. We hope that Barca lose points against Sevilla and we will win at home. I am not a champion yet [in Spain] but I hope to achieve that at the end of the season."