Villarreal's second straight defeat left them fifth in the table, two points behind Real Madrid in fourth, having played two games more.
Ronaldo had a shot blocked, and goalkeeper Geronimo Rulli had to be alert to deal with the follow-up effort from Marco Asensio.
"I don't split loyalties, I hope it is a great game and the best team wins", the retired maestro said.
Toni Kroos curled home the third from outside the area.
Sergio Ramos was interviewed immediately after the comfortable victory and also had a message for the Real Madrid supporters.More news: Duke snaps losing streak by dropping Georgia Tech
Ronaldo then got his name on the scoresheet in the 27th minute as he turned home Marcelo's low cross in the box to double Real's lead.
"Now it's time to rest well and, starting tomorrow, think about the Champions League".
"There were things in the second half that were more complicated, but I'm sticking with the positives, with the five goals and our start to the match".
Benzema, who moved to the Spanish capital in 2009 from Lyon, is the fifth highest goal scorer in Real Madrid's history. Modric was only introduced by Zidane for the final 30 minutes.More news: United States shares snap larger a day after coming into a 'correction'
Portuguese captain and Blancos record-breaking goalscoring bagged his hat trick in the second half to completed Madrid's 5-2 thrashing of the visitors. That said, Sociedad have been in poor form, with eight losses and just two wins over their last eleven all-competitions matches dating back to late November.
Giovanni Sio's first-half goal was enough for Montpellier to earn a 1-0 triumph at basement side Metz, while Guingamp and Caen played out a goalless draw at Stade du Roudourou.
Monaco wing-back Fabinho has revealed his time with the club is "coming to an end", which will alert Manchester United, who were interested in the 24-year-old Brazilian last season.
However, their consolation goal finally arrived in the 74th minute.More news: Canadian Figure Skaters Drop Horniest Part Of Routine To Secure #1 Spot
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