Garcia was sent off last month as Real Madrid ran out with a massive 3-1 win but he made the most of two glaring errors this time around to net a brace in the first half while Karim Benzema pulled one back 17 minutes from time.
The win sends Athletic Bilbao to the finals of the Spanish Cup who are set to face Barcelona on Sunday in Seville, a repeat of the 2015 final that Barcelona won 5-1 on aggregate.
This year’s Super Cup was moved to southern Spain after the coronavirus pandemic stopped it from being held in Saudi Arabia for a second straight season.
Athletic Bilbao who were bolstered with the arrival of new coach Marcelino Garcia Toral, hired less than two weeks ago in a bid to overturn the team’s fortunes. Toral has brought them to the Spanish Cup final in just his second match in charge of the club having lost 3-2 at home to Barcelona in La Liga last week.
Garcia got an ideal start for Athletic when he pounced on a mistake in the Real Madrid defence to get on the end of a through ball and score the first goal of the game in the 18th minute.
Garcia then doubled the advantage for Athletic Bilbao by sending Real goalkeeper Thibaut Courtois the wrong way from a spot-kick in the 38th minute, after Vazquez had hauled down Inigo Martinez. His second defensive error on the night.
Iker Muniain should have added the cherry on top early in the second half but he missed the target with a free header while Real Madrid’s Marco Asensio hit the woodwork twice after which Benzema pulled Real back into contention.
The Frenchman’s strike had initially been ruled offside but was awarded after a VAR review.
Benzema was also caught offside having put the ball in the net again following a VAR review.
Real searched for an equaliser deep into six minutes of added time with Athletic Bilbao surviving an agonizing wait for a VAR check to be completed on a potential Real penalty but they were spared and wildly celebrated the win.
They would go on to face Barcelona in the Spanish Cup final on Sunday.