The Ballon d’or holder’s dismissal was the first straight red card in his 16-year career and just the second time he has been sent off.
Real Madrid emerged 3-1 victors on the day with Karim Benzema, Toni Kroos and Lucas Vazquez all getting on the score sheet but it was Modric’s dismissal early in the second half which threatened to derail Los Blancos’ superiority.
Modric caught Denis Suarez at the back of his Achilles and was given his marching off orders following a Video Assistant Referee(VAR) review by referee Estrada Fernández.
Taking to social media to after the game, the former Tottenham Hotspurs midfielder protested his innocence to deliberately cause harm.
"Sent off for an accidental action," he wrote on Twitter, "In life I would never intentionally make such an action on a player. Totally involuntary!"
Real Madrid captain Sergio Ramos was however in favour of VAR being used to clean out bad tackles from the game when asked of his opinion about the technology.
"Everything used to protect football is good," Ramos said.
"Today the decision was against us. We ended up with one less man, I don't think Modric went in with bad intention but he arrived late and the referee had doubts.
"He spoke to the other officials and reached that decision. VAR's there to help us and if these decisions protect football then they are welcome."
Real Madrid’s win has given them a head start over rivals Barcelona, who lost 1-0 at Athletic Bilbao on Friday.