Sergio Ramos and Gareth Bale also netted for Julen Lopetegui's European champions, who appear to have put the disappointment of their Super Cup defeat to neighbours Atletico Madrid earlier this month behind them.
“We were trying to force things in the first half attack-wise and misplacing too many passes,” Lopetegui said. “Of course, you play better when the scoreboard is in your favour.
“Girona pressured us in the first half, making life difficult for us and the side showed their collective mentality to come through it.
"The side is functioning and when they do so, goals come. The important thing is that we score goals, not who scores them.”
After seeing Benzema denied by a linesman’s flag in the opening stages, Real were given an early scare and found themselves behind after 17 minutes when former B-team player Borja Garcia put the Catalans in front with a composed finish.
Real were indebted to a number of fine saves from goalkeeper Keylor Navas, who was selected ahead of new signing Thibaut Courtois, as Eusebio Sacristan’s side looked to double their advantage.
However, Girona were made to pay for their profligacy when Marc Muniesa felled Marco Asensio in the box just before half time.
Ramos coolly chipped the ball into the roof of the net from the ensuing penalty and from then on it was one-way traffic.
Benzema was twice thwarted by Girona stopper Bono following the restart, however, he was not to be denied when Asensio won another spot kick after he was crudely brought down by Pere Pons.
Captain Ramos allowed the France forward to take the kick and put Real ahead.
With the home side chasing the game, Real were a constant threat on the counter and Bale gave a glimpse of his searing pace when he latched onto an Isco through ball to score in his sixth consecutive league appearance.
Welshman Bale then set up Benzema’s second from close range ten minutes from the end to seal victory for Real, who have maximum points after two games, while Girona remain on one.
Earlier on Sunday, goals from Esteban Granero and Borja Iglesias helped Espanyol defeat Valencia 2-0.
(Reporting by Joseph Cassinelli, editing by Pritha Sarkar / Ian Ransom)
Share
