Celta Vigo held Barcelona to a 1-1 draw in the first leg of the round of 16 in the 2018 Copa del Rey on Thursday.
Jose Arnaiz opened the scoring for the Blaugrana after 15 minutes, but the hosts equalised through Pione Sisto midway through the first half at the Estadio Municipal de Balaidos.
Celta were impressive as they restricted Barca's usual dominance, and they have a puncher's chance of success when they travel to Catalonia for the return leg.
Barca fielded a rotated team, with long-term absentee Ousmane Dembele not selected as a starter as he makes his recovery in the squad.