Barcelona stunned by Real Sociedad in controversial defeat

La Liga leaders Barcelona suffered a 1-0 defeat against Real Sociedad on Sunday, as a Robert Lewandowski goal was controversially ruled out. Barcelona manager Hansi Flick criticised the decision, calling it a "big mistake".

Earlier in the day, Julian Alvarez's strike secured a 1-0 win for Atletico Madrid against Mallorca, lifting the Rojiblancos into third place.

Sheraldo Becker's 33rd-minute goal handed Barcelona their second league defeat of the season. Despite playing an extra match, Barcelona sit six points ahead of second-placed Real Madrid.

Lewandowski's disallowed goal in the first half sparked debate over whether the Polish forward had been offside. "It was the wrong decision, clearly, it's clear, but we have to accept it," Flick told Barca One. "The referee, it was not his fault, we are humans, we make mistakes and today was a big mistake."

Barcelona missed the energy of teenage star Lamine Yamal, who was sidelined due to an ankle injury picked up during their Champions League victory at Red Star Belgrade. For the first time this season across all competitions, the Catalan side failed to score a single goal or register a shot on target.

"The responsibility for this defeat is on us, we are responsible, we can play much better," admitted Flick. Midfielder Pedri echoed this sentiment to Movistar, saying, "Normally we score goals but today we weren't accurate...I think the team is working well and (not scoring) is not something that worries me."

Playmaker Dani Olmo started on the bench, while defender Pau Cubarsi wore a mask after suffering a facial injury in Serbia.

Barcelona struggled once again in San Sebastian, with Lewandowski's 13th-minute goal ruled offside after a VAR review. The decision stirred controversy in Spanish media, as the semi-automated offside technology suggested Lewandowski's boot was marginally offside, though it appeared the technology might have confused Aguerd's heel with the forward's boot.

Real Sociedad in Control

With Barcelona's goal disallowed, Real Sociedad took command, repeatedly testing Barcelona's goalkeeper Inaki Pena. Takefusa Kubo forced Pena into action with a low drive after a skilful dribble from the right, and Becker soon put Real Sociedad ahead with a precise low finish after Luka Sucic's header set him up.

Flick introduced Dani Olmo at half-time, but the visitors continued to struggle. Becker and Ander Barrenetxea missed further chances, while Barcelona failed to pose any real threat in the final stages, despite having scored 40 goals in their first 12 league games this season.

"We really wanted to win at home and there was no better team to do it against," said Real Sociedad's Brais Mendez. "They are the most in-form team in Europe and the fans deserved a night like this."

Meanwhile, Atletico Madrid claimed a fourth consecutive win in all competitions. Julian Alvarez scored in the 61st minute against Mallorca after being set up by Giuliano Simeone, Diego Simeone's son. "We knew it would be a tough game...we took three important points," commented Alvarez.