Malaga coach Manuel Pellegrini's first return to Santiago Bernabeu Stadium since being replaced by Jose Mourinho was far from impressive as Karim Benzema opened after 27 minutes and Angel Di Maria and Marcelo made it 3-0 by halftime.
Ronaldo scored his first in the 51st then Benzema made it 5-0. Ronaldo scored a penalty before matching Lionel Messi's league-high tally of 27 goals in the 77th, although the Portugal forward was forced off with an injury.
Both teams finished with 10 men, although Madrid was forced to as Ronaldo's exit came after Mourinho had made all three changes. Ronaldo ended a five-game run without a goal by taking his season tally to 37 to keep Madrid perfect at the Bernabeu after 21 games.
But Mourinho said afterward that Ronaldo's injury could be serious.
“At halftime I told the players the game was won - but we have to carry on,” Mourinho said. “The opponent was tired and, naturally, if you don't push a lot more goals would still arrive.” Barcelona won 1-0 at third-place Valencia on Wednesday to provisionally move 10 points out on Madrid, which responded to the pressure by scoring at least five goals at the Bernabeu for the fifth time this season.
Pellegrini greeted Mourinho before the start despite the Portuguese coach's disparaging remarks a day earlier when he ridiculed the Chilean coach's decision to lead a smaller club after being fired by Madrid.
“No words needed to be exchanged,” Pellegrini said. “It was just the logical thing to do considering the situation.” Malaga certainly played the part of inferior opponent as it sat back defending while Mesut Oezil and Ronaldo nearly scored first before Benzema broke the deadlock. The France striker positioned himself in front of defender Manuel Torres and used the outside of his right foot to guide home Xabi Alonso's cross into the area.
Argentina forward Di Maria raced in alone on goalkeeper Willy Caballero in the 36th to score when Marcelo's pass skipped over the foot of defender Manolo Gaspar.
Pellegrini looked on helplessly as Madrid blitzed Malaga's defense with one attack after another, and Di Maria found Marcelo with a well-played lob to the left for the Brazilian to send a rising shot past Caballero just before the break.
Caballero denied Ronaldo before the Portugal forward received from Oezil in the 51st and slipped free into the area to fire past the Argentine goalie.
Madrid's offense didn't relent as Benzema guided in Marcelo's cross for his fifth league goal of the season in the 62nd.
Gaspar was red-carded for handling inside the area in the 67th and Ronaldo stepped up to convert his sixth penalty of the season with a rising dagger of a shot.
Caballero stopped Benzema and Ronaldo right after the spot kick before Ronaldo's deft glance directed substitute Sergio Canales' cross past him for the last in the 77th.
Ronaldo, who scored at least three goals for the fifth time this season, limped off in discomfort immediately.
Pellegrini said the result wouldn't affect his team as it focuses on the relegation battle. Malaga was second from bottom following its biggest defeat of the season.
“We had a limited team with six injuries so it was going to be hard to get a good result,” Pellegrini said. “I don't think it will affect us since the team we used tried to play a good game. Our mentality was really focused on the game against Osasuna on Sunday, which is a final for us.” After 26 rounds, Barcelona leads with 71 points, Madrid has 64 and Valencia 51. Villarreal, which beat Hercules 1-0 on Wednesday, has 50.
Earlier Thursday, Almeria rallied to draw 1-1 against 10-man Racing Santander.
In other games, it was: Espanyol 1, Mallorca 2; Sevilla 3, Sporting Gijon 0; Zaragoza 2, Athletic Bilbao 1; Getafe 1, Atletico Madrid 1; Osasuna 0, Deportivo La Coruna 0; and Real Sociedad 1, Levante 1.
