Barcelona suffered their first LaLiga defeat of the season after going down 4-2 against Osasuna at Estadio El Sadar. (More Football News)
Ante Budimir scored twice, while Bryan Zaragoza and substitute Abel Bretones were also on target for the hosts, who claimed their first league win over the Blaugrana in nine attempts.
Osasuna were unbeaten in their six previous home league games and took an 18th-minute lead when Budimir nodded home from Zaragoza's cross.
The latter, who is on loan from Bayern Munich, doubled the advantage 10 minutes later when he rounded off a swift counter.
Pau Victor halved the deficit eight minutes after the restart, but Budimir's 72nd-minute penalty put the hosts back in control, before Bretones made it 4-1 with seven minutes remaining.
Lamine Yamal climbed off the bench to reduce Barca's arrears, but it was a consolation for Hansi Flick's side, who dropped their first points this term.
Data Debrief: Flick misses out on matching Martino
Flick was aiming to become only the second Barca manager after Gerardo Martino in 2013-14 to oversee eight straight victories at the start of a LaLiga season.
However, he and the visitors were denied by their inspired hosts, who have now recorded four successive home league wins for the first time since September 2011.
