The win enabled Real Madrid to easily overtake Barcelona. Karim Benzema put the hosts ahead after 12 minutes, before Toni Kroos doubled the advantage with three minutes left before half time at Valdebebas.
Ferland Mendy’s goal just after the hour mark was ruled out for offside following a VAR review.
Victory for Los Blancos, was enough for them to leapfrog Barcelona, who hammered Alaves 5-1 on Saturday.
Leaders, Atletico Madrid remain five points clear with two games in hand on Zinedine Zidane’s side.
The only negative from the afternoon came when Dani Carvajal limped off with an apparent hamstring injury.
Real were already without seven players due to fitness issues and midway through the first half, they lost Carvajal to yet another injury on his return to action, taking the total number of injured defenders in their squad to five.