Sevilla had started the afternoon on the same number of points as Madrid in joint fourth, but the sides looked worlds apart as Real scored all five goals before halftime to close to within five points of Barca at the top of the table.
Nacho got the hosts off to a perfect start before Ronaldo doubled his La Liga tally for the season with a cool finish and a penalty inside the half mark.
Toni Kroos and Achraf Hakimi rounded off the rout as Real leapfrogged cross city rivals Atletico Madrid into third.
Barca can regain their eight-point advantage over Real when they visit Villarreal on Sunday.
Real’s spirits were lifted even before kick-off as Ronaldo showed off his record-equalling fifth Ballon d’Or to an adoring Santiago Bernabeu.
There had been concern in Madrid ranks all week at the European champions’ lack of defensive options with Sergio Ramos, Dani Carvajal and Casemiro all suspended and Raphael Varane injured.
However, it was Sevilla who looked like the side without a defence as they gifted the hosts the opener after just three minutes.
A harmless corner to the back post saw Sevilla duo Simon Kjaer and Luis Muriel get in each other’s way and present Nacho with a gift to fire home from point-blank range.
Ronaldo has just become the first player to score in all six games of a Champions League group, but there had been a stark contrast between his stunning European form and his lack of goals in La Liga.
On Saturday, Ronaldo struck twice. The Portuguese swept home Marco Asensio’s lovely through ball to double Madrid’s advantage.
Ronaldo’s penalty then had just enough power to beat Sergio Rico after Jesus Navas handled inside his own area.
Only a fine reaction save from Rico prevented Ronaldo completing a first-half hat-trick moments later.
However, the Madrid goals kept coming before halftime as a lovely one-two on the counter-attack between Kroos and Lucas Vazquez left the German midfielder with a simple finish.
Hakimi then made it five with his first Madrid goal from a narrow angle after being played in by Benzema’s inch-perfect pass.
With Madrid facing a busy fortnight as they jet off to Abu Dhabi to defend the Club World Cup this week before hosting Barca, Zinedine Zidane’s men understandably took their foot off the gas after the break.
Ronaldo, Luka Modric and Kroos were all withdraw, but Real could easily have added to their tally as Benzema’s diving header came back off the post.
Yet, a first five-goal haul in La Liga season in undoubtedly Madrid’s best performance since they swept aside Barca in the Spanish Super Cup in August was more than enough to set up the Catalans’ return visit on December 23 nicely.