It was the unusual suspects - Clement Lenglet and Jordi Alba - who scored the goals that took Barcelona another step closer to their 26th title.
Ter Stegen, Semedo, Piqué, Lenglet, Alba, Rakitic, Arturo Vidal (Sergi Roberto, 90'), Arthur (Busquets, 56'), Messi (c), Suárez y Dembélé (Coutinho, 71').
Rulli, Zaldua, Llorente (Sandro, 86'), Aritz, Aiben, Zubeldia (Sangalí, 54'), Ruben Pardo, Merino, Juanmi (Barranetxea, 86'), William José, Oyarzábal (c).
1-0 min. 45 Lenglet. Saque de esquina de Dembélé y Lenglet marca de cabeza. 1-1, min 62 Juanmi. Balón en profundidad de Merino para Juanmi que bate a Ter Stegen con un disparo cruzado; 2-1 min. 64 Alba. balón de Messi para Alba y el lateral conecta un disparo cruzado.
González Fuentes (c. asturiano). Amonestó a Merino (15') por entrada a Messi,
Camp Nou. 75.470 espectadores
They struggled at times but eventually overcame Real Sociedad at Camp Nou, restoring their nine point lead on Atletico Madrid at the top of the table, with five games to go.
Ernesto Valverde picked a strong line up, in this, the first of three matches in which Barcelona could seal the title, which will be their eighth in 11 seasons.
However the coach did rest Sergio Busquets, Sergi Roberto and Philippe Coutinho, with Arturo Vidal, Nelson Semedo and Ousmane Dembele stepping in.
The first half was a turgid affair, with Sociedad maintaining a tight defence which Barcelona struggled to break down.
Lionel Messi came close with a free-kick whipped over and another good run by the Argentine saw a chance created for Luis Suarez, but he was offside.
Marc-Andre ter Stegen made a decent save to deny Juanmi and Willian Jose fired the rebound over the bar when he might have scored.
Suarez nearly sent Barcelona ahead just before half-time but his shot was well saved by Geronimo Rulli, and the Uruguayan’s botched rabona cross on the rebound succinctly summed up their first half display.
Dembele curved an effort narrowly wide of the far post after the break as Barcelona hunted for a second.
Juanmi levelled for Real Sociedad after a succulent through ball by Mikel Merino found him in the box.
However La Real enjoyed parity for under two minutes, with Messi feeding Jordi Alba who cut inside and curled home superbly with his right foot.
Arturo Vidal might have added a third but could not net from close range as he flung himself at a cross which crept through to the back post. It didn’t matter.