Lamine Yamal and Raphinha struck to earn Barcelona a 2-0 win over Real Sociedad on Monday, taking their team second, a point above Catalan rivals Girona.
Defeat is a setback to La Real's ambitions of playing Europa League football next season, leaving them seventh behind Real Betis, who won on Sunday.
Last season's champions Barcelona are playing for nothing but pride in the final weeks of a disappointing campaign, and finishing above high-flying minnows Girona is imperative to achieve even a modicum of that, reports AFP.
Real Madrid sealed their title win at a canter after Barcelona were beaten 4-2 by Girona little over a week ago.
Barca's brightest light Yamal opened the scoring after 40 minutes and Raphinha added a late penalty to seal the win.
"La Real are a great team, it's an important victory for us, we had a good game in general," Barca coach Xavi told Movistar.
Xavi benched Uruguayan centre-back Ronald Araujo, bereft of form this season and whose red card against Paris Saint-Germain contributed heavily to their Champions League collapse.
With Madrid swiping La Liga back off the Catalans, they end the season trophyless and licking their wounds.
Xavi, who will stay in charge next season after ditching his exit plan, started defender Inigo Martinez in place of Araujo and Pedri Gonzalez in midfield.
The Canary Islander is still building form and fitness after a string of injury problems ahead of Euro 2024, and helped Barca control the game.
Striker Robert Lewandowski was unusually active in his team's pressing, perhaps motivated by the race to finish as La Liga's top scorer.
At the other end Marc-Andre ter Stegen denied Sheraldo Becker after he burst beyond Pau Cubarsi, but the Suriname international had pushed the young defender in any case.
Shortly afterwards Becker got in behind Barcelona's high line again and this time fired home, but was correctly flagged offside.
Real Sociedad stopper Alex Remiro saved well from Yamal after the 16-year-old winger combined with Ilkay Gundogan to break into the area.
Raphinha struck the post towards the end of the first half with a long-range effort and Gundogan turned the rebound over after it fell to him at an awkward angle.
It was a warning Real Sociedad did not heed with Yamal sending Barca ahead soon after.
Lewandowski fed Gundogan well with a low through-ball and the German teed up the winger to steer home his fifth league goal of the season.
- 'We leave here hurt' -
Barcelona started the second half strongly with Raphinha twice coming close with fine long-range efforts.
Real Sociedad almost levelled when Brais Mendez won the ball back high up and fired inches wide of Ter Stegen's far post.
Remiro denied Barca substitute Ferran Torres and Yamal's effort was deflected wide after a fine solo dribble with the hosts struggling to kill off the game.
Eventually they managed it when Alvaro Odriozola's handball led to a penalty -- with VAR calling the referee to check the incident long after it occurred -- and Raphinha dispatched it with aplomb.
"They took a few minutes to go to the VAR (but) if they gave it then it was a penalty," said Real Sociedad midfielder Benat Turrientes.
"We leave here hurt, we came to win, we've got a lot on the line to try and get into Europe and I think we had chances, especially in the first half, to go in front.
"If you don't score these teams end up scoring against you."
Xavi took off Lewandowski with 15 minutes remaining and the Polish forward, who has 17 goals to his name this season in La Liga, trailing Girona's Artem Dovbyk by three, did not seem thrilled by the decision.
"We needed more fuel, more legs, we put in great effort and Robert did very good work," said Xavi.
"I understand Lewandowski's annoyance, I didn't like being taken off either."
Barcelona face Almeria on Thursday and Rayo Vallecano on Sunday as they try to stay in second place.