Ronaldo took centre stage for Jose Mourinho's side as he fired in a second-half hat-trick to take his tally in the league this season to 21 from as many games.
Sergio Ramos opened the scoring for the hosts after 54 minutes to set Madrid on their way to a victory that closes the gap on leaders Barcelona to 12 points ahead of their match against Osasuna later on Sunday.
The display will go some way to improving the mood in the Madrid camp, after a week spent denying allegations of a rift between Mourinho and a group of key players at the Bernabeu.
"I think we can see the team's improvement. In the first half we had chances that least year went in but this year it's been a bit more difficult, but when we score the first goal we have the defensive solidity from last year and in attack we are regaining the confidence that allows you to win games as we have just done," said Real No2 Aitor Karanka.
Furthermore, he praised the contribution of the clash's great star: "When a player like Cristiano is in the kind of form that he's in, he lets his goals do the talking."