Gonzalo Higuain opened the scoring against Malaga and Ronaldo, the world's most expensive player, rattled in three more before the break to take Real's goal tally to 25 from their last six games in all competitions.
Barcelona were denied by an inspired performance from goalkeeper Javi Varas who crowned his display with a stoppage-time penalty save from Lionel Messi as his side finished with nine men at the Nou Camp.
"Our first half was fantastic and that's where we won the game," Ronaldo told reporters.
"I haven't taken the match ball because I don't have space for them all," he added, after his third three-goal haul this season.
The Asturians pushed north-coast rivals Racing Santander down to 20th on goal difference after Hector Cuper's winless side suffered a 1-0 home defeat to Espanyol.
Both Malaga and Real had penalty appeals waved away in a pulsating start at the Rosaleda, but the hosts were unable to stay the pace as Jose Mourinho's side ripped into them.
Di Maria also laid on the second, his dipping cross from the right being side-footed home by Ronaldo and the knockout blow came when Malaga's defence parted for Ronaldo to fire in from outside the area just five minutes later.
Sevilla goalkeeper Varas pulled off a string of impressive saves against Barca and when he was eventually beaten in the second half Andres Iniesta´s lob bounced on the crossbar.
Varas saved Messi's spot-kick and Sevilla defender Fernando Navarro was also sent off in the tense last seconds as he brought down Pedro on the edge of the area.
"I think we played a good game, but goalkeepers also play and we have to congratulate Varas for a great performnace today," Barca coach Pep Guardiola said.
