FC Barcelona were held to a 2-2 draw at Osasuna - despite a first ever senior goal for teenager Ansu Fati.
The defending champions struggled to create chances in the absence of injured trio Lionel Messi, Luis Suarez and Ousmane Dembele , and they fell behind on seven minutes.
Osasuna striker Roberto Torres took advantage of some loose marking at the far post, to volley home Brandon's deep cross.
Ernesto Valverde reacted at half time by bringing on Fati, for Nelson Semedo, to try an inject some lief into their attack.
The 16-year old came off the bench to become the club's second youngest ever player - at 16 years and 298 days - and he broke another record as their youngest ever La Liga scorer on 51 minutes - heading home Carles Perez's cross.
Perez was the provider again as La Blaugrana took the lead on 64 minutes, as he fed substitute Arthur Melo to fire home from just inside the area.
However, despite clawing themselves back into the game - FC Barcelona were unable to hang on - as Torres returned to hanut them with an 81st minute penalty following a Gerard Pique handball.