A young boy with train-track braces in blue and red like Barça defeated the giant that couldn’t be defeated, he and his friends standing tall in the place where everyone else falls. There were 13 minutes left in the opening clásico of the season, the first of a new era that wasn’t supposed to be theirs, when Lamine Yamal Nasraoui Ebana bared his teeth.

Bared his teeth, pointed at the name on his shirt and danced with Alejandro Balde for a bit, four celebrations in one starting with a calm down, I’m here: down in the south-west corner of the Santiago Bernabéu smiling, the ball in the net for the third time, victory secured and history written. Maybe a new future too.

As teammates ran towards Lamine Yamal, on the other side of the stadium Marc Casadó tried to lift the coach, Hansi Flick, into the air and up in the directors’ box the president, Joan Laporta, sitting to the left of the presidents of Real Madrid, the region of Madrid and the senate, tried to contain himself, only a wink aimed at a Barcelona fan daring to wave his scarf below cracking the surface to reveal how wild he was going inside. To Lamine Yamal’s right, the Madrid midfielder Eduardo Camavinga passed: still walking to the bench having been replaced by Brahim Díaz, rescue mission now aborted before he even got back, he had the best view of the goal that ended it. Behind him, unheard yet, some fans spat abuse at Lamine Yamal. Go and sell hankies at the traffic lights, one shouted. How about I do this instead, you stupid racist bastards.

Asked what Madrid’s players had said about his goal afterwards, Lamine Yamal replied “that they didn’t know I had a right foot”, but he had just used it to send the ball screaming past Andriy Lunin to effectively end the clásico. Mostly, Madrid’s fans just sat, stunned and silent, although a lot of them made their way to the exit. By the time Raphinha scored the fourth, maybe a third of the 78,192 that came had gone already. It was done: no epic, inevitable Madrid comeback and no collapse of their victims, no turning this into an asylum, no fear paralysing opponents. At 2-0, maybe there was a chance – at 2-0 there were chances, in fact, Kylian Mbappé twice denied by Iñaki Peña – but not now, not with the only club that seems to like coming here.

Madrid were going to lose at home for the first time in 18 months, their undefeated run in La Liga halted at 42, one short of Barcelona’s record. The team who had won seven of the last nine clásicos in La Liga, and put four past Barcelona in January’s Super Cup, the European and La Liga champions who had then gone and signed Mbappé, the team that were going to walk the league, were beaten and like this. In the stadium where they can’t hold concerts, Barcelona gave a recital. A festival, AS called it. It had been a “bath,” Marca said; a “battering”, El Mundo Deportivo called it, one to be celebrated. Asked what music had played down in the dressing room, where Wojciech Szczesny lit up, the players sang for three days off and Flick gave them two as planned, Lamine Yamal laughed. “Well,” he said, “some of them are quite old… ”

Barcelona have made a habit of big wins at the Bernabeu. Since 2006, there have been three 3-0s, a 2-3, a 3-4, and a 2-6 while this was a third 4-0 since 2015, yet no one expected this. No one truly expected any of this. Flick though has transformed everything and everyone, quietly making Barcelona the best team in La Liga; if there was a winner from the clásico, from the season so far, it is him. “It’s incredible: he has changed the dressing room radically,” Lamine Yamal said. “You see it in the way we play, how we enjoy it on the pitch. We have a lot of respect for him and he has not had to shout or anything, it’s earned naturally. He’s an amazing coach.”

Raphinha, the winger who had felt unwanted by Xavi, the former coach, and who had spent the summer listening to people say he was on his way, one of the few sellable assets Barcelona had, had become probably the best player in Spain, with nine goals and six assists in all competitions. Robert Lewandowski, the striker that Xavi hadn’t wanted, accused of being past it, looked like Lewandowski again, scorer of 12 goals in just 10 games. Dani Olmo, the one signing he asked for, and part of the reason they let Ilkay Gündogan go, had been superb, and then injured. Marc Bernal had been brought into the team, Flick telling the club that they didn’t need to sign a central midfielder after all, and had been a revelation at 17. When he tore a cruciate, so was Casado.

Together, they were the best team in Spain: faster, more direct and harder working than ever before. Over the last week alone, they covered more than 30km more than Madrid. Barcelona began the week top of the table, having lost just once all season, against Osasuna, and won the other nine. They had put four past Girona and five past Villarreal. In their last three games they had got five against Young Boys, three against Alavés and five against Sevilla. They had scored more league goals than anyone else in Europe, on 33, and forced more offsides than anyone else too, with 65 – an average higher than anyone else in a decade.

Still Bayern Munich and Real Madrid would be a different matter, or so it goes. Instead, they scored four against them both. Against Madrid they added 12 more offsides, a tactical temerity that turned out to be an expert trap into which Mbappé fell eight times, Vinícius three. None of the front three had ever scored against Madrid for Barcelona; on Saturday they all did, the clásico coming as confirmation of just how good they could be. “When we won earlier in the season, they said it was against teams from the bottom half; now we’ve beaten two of the world’s best,” Lamine Yamal said.

They had done it their way, embracing the risks. “It’s dangerous to play like that, but it works,” Peña admitted. “You need balls,” Casado said, but life is good lived on the edge if maybe not quite as much as they had in the opening 45 minutes, which is why Frenkie de Jong came on for Fermín López at half-time to give them control of a game that had been wild until then, the threat feeling constant if often proving virtual, attacks everyone saw, one of which the Bernabeu celebrated when Mbappé clipped in a neat finish, rendered non-existent by the flag or the VAR. “We had more possession and that changed the game,” Flick said, and while there were still chances for Madrid, it ended ended up pretty well perfect.

Right down to Olmo coming on like he had never been away; Peña getting the opportunity to prove himself, the doubts washed away; and Gavi being given a clasico to get a few minutes closer to recovery and using it to crash into Vinícius, get a yellow yard and hold four fingers up, which wasn’t quite quite Tonny Bruins Slot or Gerard Piqué, a finger short of a manita, but did sort of sum it up. Even Flick’s disbelief at Lewandowski missing an open goal worked out nicely, the coach falling head over heels backwards just like the fans have, and didn’t cost them. They had done it, their way.

With six under-21s in the starting XI and eight La Masia graduates playing. With a back-up goalkeeper and a back-up to the back-up who they had pulled off the beach in Marbella, retirement interrupted. With one central defender who is 17, and the other who is 33, up against Vinícius and Mbappé. With López, a No 10 who was on loan at third-tier Linares a little over a year ago. And Casado, a central midfielder, the best player on the pitch, who spent last season with the B team and was unknown two months ago. And with a coach who has made sense of it all.

With second half goals that were the embodiment of the new, direct Barcelona: two from Lewandowski, 141 seconds between them, one from Raphinha and another from the 17 year kid who Luis de la Fuente says is touched by the wand of God, who was anointed by Him too, the kid who had just become youngest goalscorer in the history of the clásico and looks it, standing there at the Santiago Bernabéu with a twinkle in his eye and on his teeth.