Robert Lewandowski scored twice and Lamine Yamal added a third goal to ruin Kylian Mbappé's first Clásico as Barcelona romped to a 4-0 win over Real Madrid on Saturday.

Lewandowski scored from a superb pass by Barcelona's latest youth talent Marc Casadó in the 54th minute and headed in a second goal three minutes later to silence Santiago Bernabéu Stadium.

Those were goals 16 and 17 overall for the Poland striker this season, taking his league-best tally to 14. He also hit the post.

Yamal made it a rout in the 77th when the 17-year-old phenom rifled a shot from an angle over goalkeeper Andriy Lunin to become the youngest Clásico goal scorer. Raphinha got involved in the burgundy-and-blue party when he broke free with Madrid pressing forward and chipped Lunin in the 84th.

Mbappé had a frustrating first game against Barcelona in a white shirt.

The France star was repeatedly caught offside by Barcelona's synchronized back four and failed to beat second-choice goalkeeper Iñaki Peña one-on-one with his team down two goals.

Hansi Flick, meanwhile, had a night to remember in the first Clásico for the German coach.

Barcelona opened a six-point lead at the top of LaLiga over second-placed Madrid after 11 rounds.

After four consecutive Clásico defeats, the Catalans claimed their first triumph over Madrid since March 2023 in style with a clinical performance in which they were true to coach Flick's ideas of gambling with an aggressively high defence.

"We had a tough week with tough games, but we knew how to pull it out. We played a great game," Casadó, an unknown reserve team player until Flick picked him to be his holding midfielder, said after his impressive outing.

Casadó was one of five homegrown players whom Flick put in his starting lineup, the same XI that beat Bayern Munich 4-1 in the Champions League three days before. A total of six players under 22 years old started for Barcelona, led by 17-year-olds Yamal and Pau Cubarsí, and showed no signs of being intimidated by the scenario.

Yamal upstaged Mbappé this summer when Spain beat France en route to winning the European Championship, and he did it again when he displayed the finishing touch that Mbappé was lacking. To top it off, he scored his fine goal with his supposedly "not as good" right foot.

Mbappé was ruled offside five times in the first half hour, as Barcelona pressed high. Vinícius Júnior, who featured in a fascinating duel with Cubarsí, missed a golden chance in the 21st when he shot past the post from close range.

Peña was questioned whether he was up to the task of replacing Marc-André ter Stegen, out long term with a knee injury. His strong performance, which included two stops to deny Mbappé, was his first great game in goal for Barcelona.

"Our coach said that playing a high defensive line was non-negotiable," Peña said. "It is risky to play with such a high defense line, but the effort and work of the entire team is reflected in the offside traps we are creating."

Raphinha's goal confirmed his massive step forward under Flick. The Brazil forward, who acted as Barcelona captain, has 10 goals in this campaign.

Information from The Associated Press and Reuters contributed to this report.