As Barcelona were without their talisman Lionel Messi due to injury and their problems deepened when Luis Suarez hobbled off midway through the first half.
Athletic were worthy of the point they looked like they would pick up with Inaki Williams twice testing Marc-Andre Ter Stegen, before Aduriz scored one of the goals of his career to give the Basque side a first league win over Barca since 2013.
Barça survived the early storm and supposed to take control, and although they did have possession they just could not make any combinations or play five or six passes in a row, and the first half was filled with bad touches, passes and a general rush to get things done that stopped the team from playing well.
Barça improved a little bit in the second half, with higher motivation, more accurate passing and Ivan Rakitic playing well as a substitute, but Barça continued to play well below and showed very little creativity against an Athletic side.
The rest of the attack disappears, especially Griezmann, who was satisfied with staying between the center-backs and not being an option inside the box.
They caused Barcelona problems in the first half but needed to be more conservative in the second. Patience paid off and they reaped their rewards thanks to that beautiful finish from Aritz Aduriz.
Aduriz steps off the bench and did just that, A ball from the right picks out Aduriz who is unmarked in the penalty area. He keeps his eyes firmly on the ball, judges the flight to perfection and goes for the bicycle kick. And the ball sailed beyond a helpless Ter Stegen.
Athletic Bilbao is hoping to punish Barcelona on the counter-attack. A graceful start from Athletic Bilbao .