Marc Marquez overcame a grid penalty to score his sixth straight MotoGP victory at Austin in typically dominant fashion.
Having been demoted to fourth place on the grid from pole for blocking Maverick Vinales in qualifying, Marquez leapt to second into Turn 1 as Andrea Iannone took the lead.
The Suzuki man’s time in front proved short-lived however, as Marquez got by at Turn 12 on the opening lap.
Iannone was able to stick close enough to Marquez to have a go at the Honda rider at Turn 11 on lap three, but he ran wide and was repassed by the reigning champion on the exit of the corner.
Marquez proved unstoppable from that point on, opening a two-second advantage by the end of the fifth lap and doubling that margin in the following two tours.
His lead peaked at around seven seconds, and he controlled the gap to take his first win of the 2018 season and his 12th straight triumph on American soil by 3.5 seconds.
After losing touch with Marquez, Iannone soon came under pressure from Vinales, who passed for second at Turn 1 on lap seven and enjoyed an untroubled run to the runner-up spot after that.
Iannone managed to hang on to third place for his first podium as a Suzuki rider, ahead of Valentino Rossi, who pressured Yamaha team-mate Vinales in the early laps but couldn’t find a way through.
Pre-race points leader Cal Crutchlow crashed at mid-distance during a tense scrap for fifth place, which was eventually won by Andrea Dovizioso over Tech3 Yamaha’s Johann Zarco.
It means Dovizioso retakes the lead of the championship by a single point from Marquez, with Vinales just five behind in third.
Marquez’s team-mate Dani Pedrosa salvaged seventh in a race he was unsure he would complete owing to the pain from his broken wrist.
Completing the top 10 were privateer Ducati pair Tito Rabat (Avintia) and Jack Miller (Pramac) and the leading Aprilia of Aleix Espargaro, who all crowded past a struggling Jorge Lorenzo late on.
Lorenzo had to be content with 11th, one place clear of the second Pramac machine of Danilo Petrucci.
Pol Espargaro, top rookie Takaaki Nakagami and Alvaro Bautista completed the scorers. Crutchlow remounted to finish out of the points in 19th.
Alex Rins and Hafizh Syahrin both crashed out, while Karel Abraham was forced to pull into the pits with wrist pain from his crash on Saturday.
|6||Johann Zarco||Tech3 Yamaha||20||14.231s|
|8||Tito Rabat||Avintia Ducati||20||28.537s|
|9||Jack Miller||Pramac Ducati||20||28.671s|
|12||Danilo Petrucci||Pramac Ducati||20||34.993s|
|14||Takaaki Nakagami||LCR Honda||20||39.335s|
|15||Alvaro Bautista||Aspar Ducati||20||40.887s|
|18||Thomas Luthi||MVDS Honda||20||51.115s|
|19||Cal Crutchlow||LCR Honda||20||59.055s|
|20||Xavier Simeon||Avintia Ducati||20||59.747s|
|21||Franco Morbidelli||MVDS Honda||20||1m00.513s|
|–||Hafizh Syahrin||Tech3 Yamaha||8||Retirement|
|–||Karel Abraham||Aspar Ducati||8||Retirement|