Benzema opened the point at 20 minutes when he defeated two defenders before he put the ball through the goalkeeper of Plzeň Ales Hrusk's legs.
After three minutes Casemiro doubled when Brazil rounded off its marker and headed home from the corner.
Unlabelled Benzema scored their second goal with the transferable title on 37th place with Gareth Bale helping Real to score 3-0, and Benzema returned a good minute later when he chuckled from the cross to Balei to sweep the volleyball home.
Toni Kroos finished in the 67th minute when he was attacked by a goalkeeper.
Two games in the G group Real Madrid is second in nine points with Roma Roma.
(Robert Muller Report, Michael Kahn Written, Martin Herman's Editing)