American Nicky Hayden ended world champion Valentino Rossi's run of five consecutive MotoGP wins with victory in the US Grand Prix on Sunday.
The Honda rider, who started on pole, claimed his first Grand Prix victory on his 38th start, finishing 1.941 seconds ahead of compatriot Colin Edwards.
Italian Rossi took third at the Laguna Seca track, hosting the first American Grand Prix for 11 years.
It was the Yamaha rider's worst finish this season but he remains on course for a fifth consecutive world title.
Rossi extended his championship lead to 79 points over compatriot Marco Melandri after eight of 17 rounds. Melandri was involved in a first lap crash with Brazilian Alex Barros and failed to finish.
The 23-year-old Hayden, whose previous best was third in Germany last year, led every lap of the 2.238-mile road course in the hills east of Monterey, California.
"My team and my bike, just everything felt good today and it just clicked," said Hayden.
"I just got out front and just kept going as hard as I could. Sometimes I would see the gap get small and I just rode my heart out and kept pushing, pushing.
"Today was my day thanks to my team. I mean these guys pushed me hard... every dog has his day."
Rossi was passed by team mate Edwards with a deft inside move into the Corkscrew, the track's signature turn, on the 16th of 28 laps.
Rossi, who had been critical of the track, saying it was unsuitable for motorcycle racing, attacked at the end of the race, closing to 0.371 seconds of Edwards, but had to settle for third on the podium.
"I'm happy because we have always been on the podium this year," said the Italian.
"But we had some problems. We are not at 100 percent."
Italian Max Biaggi was fourth and remains third in the standings, although he closed to within seven points of Melandri.
The US Grand Prix is the only event on the calendar that doesn't include the 125cc and 250cc classes.