Mikel Merino and Alexander Sorloth scored in each half to earn Real Sociedad a 2-1 win at Barcelona on Saturday, handing the LaLiga champions their first home defeat of the season on a day when they were celebrating their title triumph.
With the league title in the bag, there was an end-of-season feel at Camp Nou as the fans waited to see the post-game celebrations when Barca would lift the LaLiga trophy.
However, Real Sociedad made sure it would not go all Barca's way as they got in-front quickly, with Merino scoring with a tidy finish in the fifth minute.
They extended their lead with Sorloth in the 72nd minute and Robert Lewandowski headed in a consolation for Barcelona from close-range in the 90th minute.
With three games left, fourth-placed Real Sociedad moved on to 65 points and tightened their grip on the last Champions League qualification spot, five points ahead of fifth-placed Villarreal who beat Girona 2-1 earlier on Saturday.
Champions Barcelona have an unassailable 14-point lead over second-place Real Madrid, who play at Valencia on Sunday. Atletico Madrid are third on 69 points.