As a result, Barca remain second in the table behind Real Madrid, while Sociedad have moved into 13th position.
Here, Sports Mole dissects the 90 minutes of action between the two Spanish rivals.
On target: 1
On target: 4
Was the result fair?
The statistics point to a match that was largely dominated by Barcelona and while that was the case, Sociedad certainly deserved something for their efforts. Whether they deserved all three points is open to discussion, but there is no question that the home side outfought and outworked their more illustrious opponents.
Barca were always going to dominate possession and create the majority of chances, but defensively, Sociedad were simply excellent at the Anoeta. The fact that Barca boss Luis Enrique left the likes of Lionel Messi and Neymar on the bench will have handed Sociedad confidence before a ball was even kicked and they made use of that advantage on the field. Incredibly, Barca have now lost on four of their last five visits to the Anoeta.
What Sociedad lacked in ability, they more than made up for in desire. There is no question that Barca have the better players, but the home side refused to be beaten. They were a team short of confidence at the start of the season, but David Moyes seems to have instilled some belief into the side since arriving in Spain. Moyes would have been looking for a positive start and that arrived just two minutes into the match when Alba turned a Canales cross past his own goalkeeper. A response from Barca was expected and indeed it arrived, but Sociedad were prepared to put their bodies on the line.
Carlos Martinez and Inigo Martinez were both exceptional at the back, while Estaban Granero and Xabi Prieto provided defensive work and attacking guile in equal measure. Carlos Vela found it difficult to influence proceedings due to Barca's domination of the ball, but the Mexican never stopped working and provided a real outlet in the final third. Sociedad had to ride their luck for spells, with their goalkeeper making some good saves and Barca not up to their usual standards, but they took advantage. Since Moyes took charge, the Basque outfit have lost just once in all competitions and there are bright signs ahead.
There was a sense of shock around the stadium when the teamsheets were released and it became clear that Enrique had rested Messi and Neymar, in addition to the likes of Ivan Rakitic, Gerard Pique and Dani Alves. If this match arrived in the middle of a busy run of fixtures, then the decision would have been understood, but Barca have only just returned from a winter break. That said, a team that included the likes of Luis Suarez, Pedro, Andres Iniesta and Xavi should have been good enough to put on a better display. Ultimately, too many players were off-colour for the Catalan side.
Suarez is taking time to settle at Barca, while Munir El-Haddadi did not justify Enrique's faith, with the youngster struggling to make his mark before being hooked at the break. Messi and Neymar both entered in the second half, but it proved too little too late as Sociedad put 10 men behind the ball. Had Enrique started his strongest XI then it more than likely would have been a different outcome, but the Spaniard's risk backfired. The defeat will be even harder to take after Real Madrid were beaten at Valencia earlier in the afternoon. It has been some weekend for the current champions Atletico Madrid.
Sports Mole's man of the match
Inigo Martinez: In truth, this could easily have been awarded to Carlos Martinez, but Inigo just takes it. The Spaniard, who has previously been linked with the likes of Barcelona and Manchester United, was in exceptional form at the Anoeta. Not only did the centre-back make block after block throughout the match, he was also calm and composed in possession when the opportunity arose. Messi, Neymar and Suarez all struggled against the talented defender.
It is really difficult to look past Enrique for this category. Some of Barcelona's defending at the Anoeta was poor, but not as poor as Enrique's decision to leave two of his best players on the bench. Pique was also another surprise absentee and his replacement, Jeremy Mathieu, had a sloppy evening. It is difficult to ascertain just what the Spanish coach had in mind.
Barcelona felt that they should have had a penalty in the first period when Inigo Martinez appeared to handle the ball, but referee Carlos del Cerro was not interested. The away side also had misgivings about a late decision, when Neymar was penalised for a high boot on Sociedad goalkeeper Geronimo Rulli after taking possession away from the stopper. It was a busy night for Del Cerro in terms of cards, meanwhile, with nine bookings issued during what was a fiery affair.
Sociedad: The Basque outfit will travel to Villarreal for the first leg of their last-16 Copa del Rey clash on Wednesday, before returning to league action away to Granada next Sunday.
Barca: Barca are also in Copa del Rey action next week as they host Elche on Thursday. The Catalan outfit will then welcome the champions Atletico Madrid to the Camp Nou next Sunday.