Barcelona was held to a 1-1 draw at home by lowly Alavés in the debut of caretaker coach Sergi Barjuan, while Real Madrid and Sevilla both won on Saturday to leave the Catalan club even further behind in the Spanish league.
Vinícius Júnior took over the scoring duties from Karim Benzema by netting twice in Madrid's 2-1 win at 10-man Elche. Madrid, Sevilla and Real Sociedad are at the top of the standings. Sociedad can reclaim the outright lead on Sunday at home against regional rival Athletic Bilbao.
Barcelona was left in ninth and eight points adrift after four wins in 10 games.
Barjuan, a former Barcelona player who until Thursday was its reserve team coach, did not waver from the lineup and 4-3-3 formation used by Ronald Koeman, who was fired this week after one too many defeats.
The outcome was again overwhelming possession for Barcelona with very little to show for it.
Memphis Depay gave Barcelona the lead with a wonderful strike from outside the area in the 49th minute, only for Luis Rioja to dribble through the center of the hosts' painfully passive defense and equalize three minutes later.
Rioja dribbled past three Barcelona players before a quick passing combination with Joselu Mato fooled Gerard Pique and left Rioja alone to round Marc-Andre ter Stegen and roll the ball home.
Depay's shot off the post was the hosts' only clear chance for a winner.
"I had little time to work but I tried to organize my players in attack and defense and I think that went well, but when there is a negative result it is difficult to digest," Barjuan said. "There is a long way to go in the league. The only way to get back in it is by winning."
Unless Barcelona quickly finds a full-time coach, Barjuan could still be charge on Tuesday when Barcelona travels to Ukraine to face Dynamo Kyiv in a match that it needs to win to boost its chances of avoiding elimination from the Champions League group stage for the first time in two decades.
The one bright spot for Barcelona was the play of teenage midfielders Gavi Páez and Nico González, who provided the only sparks in attack besides Depay. Barjuan also gave a debut to 19-year-old Abde Ezzalzouli in the final minutes.
But Barcelona's injury list likely grew after Pique limped off in the second half after Sergio Agüero had to leave after feeling dizzy, according to Barjuan.
The Argentine had to be substituted in the 41st after he motioned to the top of his chest and throat. After spending a minute stretched on the turf, he was able to walk off. The club said that Agüero was taken to the hospital for "cardiological tests" after being bothered by his chest.
Barcelona was already without Pedri González, Frenkie de Jong, Ansu Fati, Ousmane Dembelé, Ronald Araújo and Sergi Roberto due to injury.
Only 37,000 fans turned out at the 99,000-seat Camp Nou. The rainy day and the long weekend with Monday being a holiday dampened the turnout, as did the struggles of a team still missing Lionel Messi.
Once again, the 21-year-old Vinícius showed his much-improved finishing for Madrid. The double took his tally in all competitions to nine in 14 appearances this season, compared to six goals in 47 outings in 2020-21. He is the second-leading scorer in the top tier with seven goals, behind the nine goals of Benzema, who rested against Elche.
"This is thanks to the work I have been putting in since I arrived," said Vinícius, who debuted for Madrid at age 18 after the club had secured his transfer from Brazil's Flamengo when he was 16.
Mariano Díaz played his first minutes of the season in Benzema's place. The rarely used striker showed his reflexes were still sharp when he used his heel to knock a pass from Casemiro into the path of Vinícius for him to fire under Kiko Casilla in the 22nd.
Elche was pressing for an equalizer when Raúl Guti made a dangerous tackle on Toni Kroos and was sent off in the 63rd.
Vinícius finished Elche off 10 minutes later when he chipped the ball over Casilla from a tight angle after Luka Modric played him clear with one touch.
Elche substitute Pere Milla pulled one back with four minutes to play, but it was not enough to keep his side unbeaten at home this campaign.
OSASUNA LOSES AWAY
Sevilla ended Osasuna's undefeated road record this season with a goal in each half for a 2-0 win under heavy rain at the Sánchez Pizjuán Stadium.
Defender Diego Carlos put the hosts ahead in the 40th by heading in Ivan Rakitic's corner. Lucas Ocampos added a second after a defensive error in the 60th.
Valencia beat regional rival Villarreal 2-0.