Zinedine Zidane’s men were two goals down by the 38th minute after a Raul Garcia brace. Karim Benzema pulled a goal back in the 73rd but the Spanish champions could not complete the comeback despite Benzema having an equalising goal ruled out for offsides in the 83rd.
The defeat marks Zidane’s 17th loss in 87 games managed since rejoining Real Madrid in March of 2019 — one more than he recorded in the 149 games he managed during his first stint at the club in 2016-2018.
He doubled the lead 20 minutes later from the penalty spot after Lucaz Vazquez pulled down Inigo Martinez in the area.
The goals were the first time Athletic had scored twice in a game against Real Madrid since a 4-2 loss in La Liga on Feb. 2016.
Benzema gave Real a lifeline in the final 20 minutes when he swept home from close range and a VAR review confirmed the strike. But Athletic held on to book their place in Sunday’s final against Barcelona, who beat Real Sociedad on Wednesday.