The Frenchman pounced after an attempted interception in the Getafe midfield could only guide the ball into his path.
The striker seized on the loose ball, nudging the ball past one defender before keeping his cool to fire low past Vicente Guaita.
The goal came at a key time for Real, who looked as though they were starting to become frustrated with their inability to break down their opponents.
Guaita had previously denied Ronaldo with a fine stop but there was nothing he could do on this occasion.
Check out the goal for yourself below:
ES ES EL INCREÍBLE GOL DE KARIM BENZEMA @Benzema FROM REAL MADRID @realmadrid AGAINST GETAFE LA LIGA @LaLiga#RealMadrid #Benzema #BREAKING pic.twitter.com/WZTsQE5mTu
— WOSAN (@McWOSAN) 14 October 2017