Real Madrid piled renewed pressure on Barcelona coach Ronald Koeman as David Alaba scored a scintillating goal to help seal a 2-1 victory in the Clasico on Sunday.
Real Madrid beat struggling Barcelona but Real Sociedad stay top
Midfielder Gavi (L) was the youngest Barcelona starter in a Clasico for almost 100 years
But Real Sociedad regained their place at the top of La Liga after holding off Atletico Madrid's late comeback to draw 2-2 in a thrilling game at the Wanda Metropolitano.
Luis Suarez scored twice in the second half, including a penalty, to salvage a point for Atleti, who edge up to fourth.
That match had more bearing at the top of the table, a sign of the times perhaps for La Liga, which could prove more open to challengers this season than for a long time.
Alaba's bending shot had Real Madrid in front for the majority of an end-to-end contest a Camp Nou, with Lucas Vazquez making it two in injury-time before Sergio Aguero tapped in his first goal for Barcelona with seconds left.
Barca have now lost a fourth consecutive Clasico for the first time since 1965 and drop to ninth in La Liga, five points behind Madrid, who trail Real Sociedad by one.
After beating Valencia and winning a crucial Champions League game against Dynamo Kiev this week, it is a fresh set-back for Barca and Koeman, whose future will again come under scrutiny.
Madrid, meanwhile, see their own recovery bolstered, after backing up a thumping win over Shakhtar Donetsk to leave a rocky run in the rear-view mirror.
"These games are always close," said Koeman. "They have their game, we have ours and the details decide the result. It's a shame because we had the opportunities to score."
Madrid coach Carlo Ancelotti said: "We played against a great team, we have suffered, but we were able to cope."
A first league meeting between these clubs without either Lionel Messi or Sergio Ramos since 2005 was more about the future.
For the first time in 65 years, six players younger than 22 began the game while Gavi, Barcelona's 17-year-old midfielder, was the youngest Barca starter in a Clasico in almost a century.
The promotion of a duel between Ansu Fati and Vinicius Junior perhaps felt a little forced, but both players have become symbols of hope.
Fati endured one of those games to be expected sometimes of an 18-year-old, with the occasional threat dotted across a quieter display than he would have liked.
Vinicius, though, was electric from the start, a constant thorn in Barcelona's side, especially in the first half, and instrumental in Alaba's superb, counter-attacking opener.
Barca controlled the ball early on, their more patient approach yielding a golden opportunity for Sergino Dest, the American more accustomed to right-back than right wing, who blazed over from six yards after Memphis Depay slid across.
Madrid made Barcelona pay in the 32nd minute with a wonderful goal. Alaba tackled Depay on the edge of his own box and kept going, at first wanting it down the line from Vinicius, who instead switched forward to Rodrygo.
This time Alaba would get it back, his space opened up by the curving run of Benzema, and from the edge of the area he swerved the ball inside the far post.
Barcelona grew in confidence before the hour but Madrid survived and threatened a second as Luka Modric's bending effort was blocked and then Modric teed up Benzema, who volleyed at goalkeeper Marc-Andre ter Stegen.
The game had a dramatic finish. Pique wanted a penalty when he was prevented from shooting in the box and on the counter-attack, Madrid made it two, Marco Asensio's shot swept in by the sliding Vazquez in the 93rd minute.
There was still time for an Aguero goal in the 97th, a sharp finish from Dest's cross, but not for a comeback.
Atletico came back from two goals down but Real Sociedad held on for a deserved point.
Alexander Soerloth finished off a slick counter-attacking move in the seventh minute before Atleti keeper Jan Oblak failed to stop Alexander Isak's free-kick flying into the corner just after half-time.
But Suarez headed in on the hour and then converted a penalty he won after Mikel Merino caught the back of the Uruguayan's leg. Atleti could not find a winner.