Marc Marquez continued his winning streak with a Catalunya MotoGP Sprint victory on Saturday after his brother Alex Marquez crashed out in the lead.

Polesitter Alex Marquez was comfortably ahead on his Gresini Ducati but came to grief with four laps to go, allowing his older sibling to record a 14th triumph in 15 Sprint races this season. Alex claimed the other at Silverstone.

Alex Marquez flung his arms up and down in frustration in front of his home fans after picking himself up off the gravel, as six-time world champion Marc Marquez extended his overall lead to 187 points over his brother in second.

Fabio Quartararo came second in the sprint with Fabio Di Giannantonio third.

"(I was) too relaxed and feeling a bit unbeatable in that moment," said Alex Marquez, explaining his crash when he lost the front end of his bike.

"I see many times confidence can also be dangerous... a shock of reality, but better today than tomorrow...

"It was completely my fault... too confident."

Marc Marquez's victory helped ensure Ducati, ridden by three teams, won the 2025 Constructors' World Championship title.

"I am very happy for the victory and for the Ducati team, because we have won the constructors' championship," said Marc Marquez.

"When Alex went down, I had thrown in the towel because he was going faster, but maybe at that moment he relaxed and the fall happened.

"He is still the favourite for tomorrow because he has the best pace."

Pedro Acosta on a KTM leapt into second in the first lap but Marc Marquez overtook at the start of the second to stay behind his brother, who seemed untouchable until crashing on turn 10 of the ninth lap.

That allowed Yamaha rider Quartararo to come in second, 1.299s behind Marc Marquez.

Quartararo said that finishing second "means a lot for us, above all to be here fighting with the Marquez brothers.

"This result makes me feel very happy because we came from two very difficult races and I'm really pleased."

Last year's champion Jorge Martin, still looking for his best form after injury troubles, crashed out of the race in a collision with Franco Morbidelli in lap seven.

Francesco Bagnaia started in 21st on the grid, after his worst qualifying performance since 2022, and finished 14th.