Athletic Bilbao stunned Barcelona 3-2 after extra time to lift the Spanish Super Cup on Sunday night in an entertaining match.
Antoine Griezmann scored a brace for Ronald Koeman's side, but a resilient Bilbao, which stunned Real Madrid in the semifinals crept back to force the match into extra time.
In another highlight point of the match, Barcelona talisman Lionel Messi was shown a red card with a few minutes to go for unsporting behaviour.
The match was a cagey affair in the opening half, with few clear chances from both sides.
The first clear cut chance fell to Barcelona in the 37th minute as Messi collected a wonderful lead pass and smashed a terrific shot from long range, but his effort went painfully close to the crossbar.
It did not take long though for Messi and company to take the lead, and it came courtesy of Griezmann, who reacted quickest to a rebound ball after the Argentine's attempt was blocked, and he fired in the opener.
The lead lasted less than a minute as Bilbao equalised in the 42nd minute after Oscar de Marcos managed to latch on to an Inaki Williams cross, and he found the back of the net for a 1-1 scoreline going into the break.
The match came to life in the second period with Barcelona on the front foot. They should have doubled their lead in the 52nd minute but Messi missed a great chance.
Bilbao then responded and found the back of the net, but their celebrations were short-lived as a VAR check ruled out the goal for offside.
Koeman's men then scored what they thought could give them the title in the 77th minute after Jordi Alba teed up Griezmann inside the box and he rolled the ball past Unai Simon to put them 2-1 up.
Just like the first half, Bilbao equalised deep in injury time as a cross from a free-kick was whipped deep into the box by Iker Muniain and Asier Villalibre got in a shot, sending the ball into the top of the net.
There was no winner in regulation time, forcing the match into extra time, and it was Inaki Williams who scored the winner after making himself some space on the edge of the penalty area before puling the trigger, which found its way into the net off the post.
It got worse for Barcelona as Messi was shown a red-card late on, meaning he will miss the club's next domestic assignment.