David Alaba's unstoppable drive just after the half-hour mark inspired Real Madrid to a fourth successive El Clasico victory over Barcelona.
Real were rarely threatened after the Austrian's 18-yard rocket but Lucas Vazquez put the result beyond any doubt when he bundled home after Marco Asensio's shot was parried four minutes into injury time.
In the seventh and final minute of added time Sergio Aguero notched his first goal for Barcelona, a typical poacher's effort volleying in from six yards, but it was scant consolation.
Barcelona should have been the side to open the scoring in the 26th minute as Sergino Dent blazed over the bar after Memphis Depay's low cross arrived to him in space eight yards.
Shortly after the goal, Gerard Pique was gifted a free header from Depay's corner but his effort flew agonisingly wide of the far post. The Azulgrana did not really come close to threatening the Real Madrid goal until substitute Aguero's late intervention.
The win puts Real Madrid top of the table while Barcelona are eighth.
It takes a leap of faith to think thank Sergio Aguero can be as prolific for Barcelona as he was for Manchester City in the years leading up to 2020 but that is the best chance Ronald Koeman has of his side being competitive in any tournaments this season.
Although their talented young players can follow Koeman's tactical plan and put themselves in position to create chances, against elite opposition Memphis Depay and Ansu Fati will not be capable of scoring the goals to win these matches.
Aguero's finish of a volley slightly behind him, and even his effort just over the bar when he expertly led his marker to the ball then backed off to head towards goal, was the kind of goalmouth expertise you cannot see other members of the Barcelona squad being able to replicate.
After Lionel Messi (30) and Antoine Griezmann (13), no player got close to scoring double figures in la Liga for Barcelona this season and other than Depay none are likely to in this campaign.
Ancelotti 'happy' to win first Clasico at Camp Nou as Real Madrid beat Barcelona
MAN OF THE MATCH - DAVID ALABA (REAL MADRID)
Like the game itself, this award is not as hard to win as it might have done a few years ago. And if Alaba had to deal with a fully fit Sergio Aguero for a whole game he may not have found the game as easy to glide through.
As it was, the former Bayern Munich star and defensive partner Eder Militao looked extremely dealing with the Barcelona forward line through the vast majority of the ninety minutes.
And the best moment of the game came from his extraordinary effort. He broke up the Barcelona attack and then fed Vinicius on the left and continued running past him up the left wing, receiving a ball from Rodrygo on the left flank where with still a lot to do he left Marc-Andre ter Stegen with no chance.
Barcelona: Ter Stegen 6, Mingueza 6, Pique 7, Eric Garcia 7, Alba 6, Busquets 7; Gavi 6, F de Jong 6; Dest 5, Fati 6, Depay 6.
Subs: Coutinho 6, Aguero 7, Sergi Roberto 6, L de Jong
Real Madrid: Courtois 7, Lucas Vazquez 7, Eder Militao 7, Alaba 8*, Mendy 6; Casemiro 6; Kroos 7, Modric 6; Rodrygo 6, Vinícius Júnior 6; Benzema 7.
Subs: Valverde 6, Asensio 6, Carvajal 6.
‘We showed we're not inferior to Real' - Koeman optimistic despite defeat in Clasico
26' WHAT A MISS! A great run from Depay down the left and he squared just behind Fati which presented Dest with a near open goal but he put it miles over the bar.
32' GOAL FOR REAL MADRID! Alaba scores a magnificent first. It came from a counter-attack and Alba started the move, then kept on running down the left flank, was found by Rodrygo and fired a missile inside the far post leaving ter Stegen with no chance.
35' JUST WIDE! Pique meets Depay's corner with a firm downward header that has Courtois beaten but drifts just wide of the far post.
90+4' GOAL FOR REAL MADRID! Asensio races down the inside left channel and puts a good shot in from a tight angle which ter Stegen saves but Lucas Vazquez taps home the rebound.
90+7' GOAL FOR BARCELONA! Aguero scores a typical poacher's goal after Dest gets around Mendy and puts a low cross on the six-yard box which the former Manchester City striker puts away with aplomb.