Match ends, Real Sociedad 1, Barcelona 2.
Barcelona scored two goals in three second-half minutes to come from behind and beat Real Sociedad to maintain their 100% start to the La Liga season.
The champions trailed after 12 minutes when they failed to clear a free-kick and Aritz Elustondo lashed in.
But Luis Suarez scrambled the ball home in the 63rd minute before Ousmane Dembele converted at another corner.
La Real could have been further in front but missed three chances shortly before the Barcelona goals.
Barca goalkeeper Marc-Andre ter Stegen made two fine saves, denying Real Madrid loanee Theo Hernandez and Juanmi while Mikel Oyarzabal blazed over at the end of a quick counter-attack.
The hosts, playing at their newly renovated Anoeta stadium for the first time, could have grabbed a point late on but Juanmi headed narrowly wide from inside the area.
Barcelona were poor in the first half and also capitalised on goalkeeping errors for both goals with Geronimo Rulli missing punches at both set pieces.
The win for Ernesto Valverde's side is their fourth from four games this season and keeps them top of the table.
Earlier in the day, Atletico Madrid needed an injury-time debut goal from Borja Garces to draw 1-1 with Eibar.
- 4IllarramendiBooked at 43minsSubstituted forMerinoat 82'minutes
- 17ZurutuzaSubstituted forBautistaat 73'minutes
- 14PardoSubstituted forSangalliat 82'minutes
- 1ter Stegen
- 2Nélson SemedoSubstituted forCoutinhoat 45'minutes
- 23UmtitiBooked at 87mins
- 12RafinhaSubstituted forBusquetsat 57'minutes
- 11DembéléSubstituted forVidalat 77'minutes
- 19El Haddadi
- Carlos del Cerro Grande
- Shots on Target
Second Half ends, Real Sociedad 1, Barcelona 2.
Attempt blocked. Mikel Merino (Real Sociedad) left footed shot from outside the box is blocked. Assisted by Luca Sangalli.
Attempt blocked. Luis Suárez (Barcelona) right footed shot from the centre of the box is blocked. Assisted by Coutinho.
Coutinho (Barcelona) wins a free kick in the defensive half.
Foul by Igor Zubeldia (Real Sociedad).
Samuel Umtiti (Barcelona) is shown the yellow card.
Foul by Samuel Umtiti (Barcelona).
Jon Bautista (Real Sociedad) wins a free kick in the attacking half.
Attempt missed. Juanmi (Real Sociedad) header from the centre of the box is close, but misses to the right. Assisted by Mikel Merino with a through ball.
Offside, Real Sociedad. Luca Sangalli tries a through ball, but Juanmi is caught offside.
Substitution, Real Sociedad. Mikel Merino replaces Asier Illarramendi.
Substitution, Real Sociedad. Luca Sangalli replaces Rubén Pardo.
Foul by Lionel Messi (Barcelona).
Theo Hernández (Real Sociedad) wins a free kick in the defensive half.
Sergio Busquets (Barcelona) wins a free kick in the defensive half.
Foul by Asier Illarramendi (Real Sociedad).
Attempt missed. Lionel Messi (Barcelona) left footed shot from outside the box is high and wide to the left.
Samuel Umtiti (Barcelona) wins a free kick in the defensive half.
Foul by Jon Bautista (Real Sociedad).