Suzuki rider Alex Rins defeated Valentino Rossi to claim his first MotoGP victory. Marc Marquez's undefeated run in Austin ended in a fall and a healthy lead.
Honda rider Marquez turned the Pole into an early lead and looked good after scoring a seventh consecutive win at the Circuit of the Americas as he extended his lead in the early laps.
He had finished second almost four seconds ahead of Rossi's Yamaha when he suffered a low-side crash in the ninth lap of the left of Turn 12, ending his race.
Marquez's death gave Rossi a narrow lead over the Rins, but the MotoGP legend, who has not won since Assen in June 2017, could not shake off the Suzuki rider.
Rins managed to get past the seventh turn in turn 7 on lap 17 to take the lead.
Rossi tried to take revenge on the tight turn at the end of the back straight, but ran wide and could never get close enough to fear another attack on Rins.
The 23-year-old Spaniard crossed the finish line in just 0.462 seconds, earning Suzuki his first ever premier class win since Maverick Vinales's victory at Silverstone in 2016.
Eight seconds behind the top pair, Jack Miller used soft tires that were missing from Pramac Ducati to claim third place – his first podium finish since his Dutch TT victory in 2016.
Andrea Dovizioso recovered from 13th to sixth in the first lap to claim fourth place behind Miller and take the championship lead.
Franco Morbidelli clinched his first top five finish for Petronas Yamaha, ahead of Ducatis second Danilo Petrucci, team-mate Fabio Quartararo and KTM rider Pol Espargaro.
Francesco Bagnaia and Takaaki Nakagami rounded off the top 10.
A miserable day for Honda was aggravated by an early crash at Cal Crutchlow on Turn 11, when he finished third behind Rossi and a mechanical failure for Jorge Lorenzo.
Vinales had another race to go, forgetting to make the start and a drive-through penalty before recovering to position 11 ahead of Andrea Iannone and Johann Zarco.
Rins' Suzuki team-mate Joan Mir also received a penalty for the same offense as Vinales, finishing 17th.
Aleix Espargaro collapsed in the second round with his Aprilia, making it the only retirement that was not Honda in the race.
|2||Valentino Rossi||Yamaha||Yamaha||20||0.462 s|
|3||Jack Miller||Pramac Ducati||Ducati||20||8.454 s|
|5||Franco Morbidelli||Petronas Yamaha||Yamaha||20||18.021s|
|7||Fabio Quartararo||Petronas Yamaha||Yamaha||20||26.111s|
|9||Francesco Bagnaia||Pramac Ducati||Ducati||20||30.608 s|
|10||Takaaki Nakagami||LCR Honda||Honda||20||31.011s|
|11||Outsider Vinales||Yamaha||Yamaha||20||34,077 s|
|14||Miguel Oliveira||Tech3 KTM||KTM||20||44.272 s|
|fifteen||Tito Rabat||Avintia Ducati||Ducati||20||44.623 s|
|16||Karel Abraham||Avintia Ducati||Ducati||20||44.740 s|
|17||Joan Mir||Suzuki||Suzuki||20||48,063 s|
|18||Hafizh Syahrin||Tech3 KTM||KTM||20||1m07,683s|
|–||Cal Crutchlow||LCR Honda||Honda||5||retirement|