Ronaldo notched up his 40th league goal of the season during the triumph at the Vicente Calderon Stadium.
The 27-year-old has now found the net 60 times in all competitions for Los Blancos this campaign.
"Cristiano Ronaldo is the best player in the world," Ramos told reporters. "We're lucky to train with him every day and to have him with us."
Madrid are four points clear of Barcelona at the top of the Primera Division table.