كتب : وكالات
Paraguayan striker Nelson Valdez scored both goals at Nou Camp to hand the newly promoted side their first win of the season.
Esteban Vigo's men ended the Catalans' 16-month unbeaten home run.
Barca's arch-rivals Real Madrid registered a hard-fought 1-0 victory over Osasuna later on Saturday.
Summer signing Ricardo Carvalho scored the only goal of the game to give Jose Mourinho his first win with the capital club.