Real Madrid have 86 points after 37 games, seven more than deposed champions Barcelona.
Benzema fired through the legs of keeper Sergio Asenjo to put Real Madrid ahead after 29 minutes and converted a penalty in the 77th to help Real on their way to a remarkable 10th consecutive win since the La Liga season resumed after the novel coronavirus (COVID-19) pandemic stoppage.
Real Madrid regained the La Liga crown after three years as they clinched a 34th title in the top flight of Spanish football with one game to spare by beating Villarreal 2-1 at home.