Austin, Texas – Marc Marquez retained his unbeaten record at the Circuit of the Americas with a superb fifth consecutive win, as Yamaha’s young gun, Maverick Vinales, slid out of contention.
Second was Valentino Rossi, who moved to the top of the points standings, having finished on the podium at every race so far this year.
With big brother Brad out of action, South African Darryn Binder flew the flag in fine style with his first ever top 10 finish in MotoGP.
Marquez fought it out with works Honda team-mate Dani Pedrosa for the lead in the early stages, before being able to break clear in the latter laps of the race to take his fifth win in a row in Austin, and his 11th consecutive win on US soil in an incredible statistic. Rossi put in a late charge to take second, with Pedrosa completing the podium after Vinales crashed out early on.
Off the line it was an absolutely stunning swoop around the outside for Pedrosa from the second row to lead – old habits die hard - as he overtook team-mate and pole-sitter Marquez to lead through Turn 1, with Rossi tucked in behind the two Hondas.
Ducati Team rider Jorge Lorenzo got a great launch from sixth on the grid to pass Vinales; the two battled it out until rookie sensation Johann Zarco (Yamaha Tech 3) got into the action and followed Vinales past Lorenzo, just before Vinales lowsided out of contention at Turn 18.
Honda privateer Cal Crutchlow came up from ninth on the grid to take the factory Ducati duo for fifth behind Zarco, with Andrea Dovizioso getting the best of Lorenzo to move into sixth.
A moment between Zarco and Rossi then saw the ‘Doctor’ off the circuit as Zarco tried to get past; Rossi rejoined a little further ahead and subsequently received a 0.3 second penalty for time gained.
It was then the Hondas’ time to duel, as Marquez and Pedrosa diced for the lead until Marquez was able to begin pulling away with 13 laps to go.
In the final stages Crutchlow passed Zarco for fourth to come home top privateer, while Rossi passed Pedrosa to take third. Andrea Iannone (Suzuki) passed the struggling Lorenzo at the death for his first points haul of the season in seventh, as did Ducati privateer Danilo Petrucci, while Honda rider Jack Miller just beat rookie Jonas Folger (Yamaha tech 3) to complete the top 10.
Franco Morbidelli (Kalex) took his third consecutive win of the season, the first man to do so in the intermediate class since the late Daijiro Kato in 2001. Tom Lüthi (Kalex) finshed second for his 50th world championship podium, while Takaaki Nakagami completed an all-Kalex podium.
Morbidelli got away in the lead from pole, with Mattia Pasini (Kalex) getting a good launch to hold onto second and Marquez threatening in third on his 21st birthday, after a slightly slower launch off the line.
A big incident into Turn 1 saw Stefano Manzi (Kalex) hit Julian Simon (Tech 3) just as another collision took down Yonny Hernandez (Kalex) Lorenzo Baldassari (Kalex), and Jesko Raffin (Kalex).
Marquez then took the lead from his team-mate and Pasini, with Nakagami, Luthi and Miguel Oliveira (Ajo) chasing the leading trio, Pasini in particular pulling some choice moves before Marquez ran wide and slotted back into fourth.
Marquez got back past Pasini before Italian veteran lowsided out of contention in Turn 1 – and Morbidelli set a new lap record.
Nakagami and Marquez debated third until Nakagami made it stick at Turn 12, and Dominique Aegerter (Suter) hunted down Oliveira to take fifth after an impressive ride and Simone Corsi (Speed Up) shot up into seventh on a circuit that has often been a good one for this – the last non Kalex to win in Moto2 was a Speed Up at Austin in 2015 - ahead of Marcel Schrotter (Suter) and another top 10 stunner from Tech 3 Racing’s Xavi Vierge and Luca Marini (Kalex).
Honda rider Romano Fenati took a stunning win, crossing the line more than four seconds clear of dueling Gresini Honnda team-mates Jorge Martin and Fabio Di Giannantonio, for his first win since the same venue in 2015, after the race was interrupted by a red-flag incident and shortened to 12 laps.
Polesitter Aron Canet (Honda) was streaking away from Joan Mir (Honda) after a near perfect launch off the line, before rookie Kaito Toba (Honda) crashed at Turn 14 and the red flags.
Canet got the hole shot again at the restart but this time it was Fenati on the chase, and he took the lead on the first lap before Canet got it back going into Turn 1. Di Giannantonio was the big winner second time off the line, moving up third, with the leaders trailed by Mir, Martin, Nicolo Bulega (KTM) and Enea Bastianini (Honda) - before the gloves came off at the front.
After a stunning side-by-side duel between the two leaders Canet and Fenati, the Italian had settled back into second - until Canet suddenly high-sided out of contention at Turn 19, leaving Fenati in the lead after some impressive tactics.
As he moved away by about a second a lap, Martin, Mir, Di Giannantonio and Bulega were ducking and diving, swopping positions in their battle for the remaining two podium spots, until the cavalry arrived in the form of Bastianini, John McPhee (Honda), Juanfran Guevara (KTM) and Philipp Oettl (KTM).
At the beginning of the final lap, it looked like a certain double podium for the Gresini duo, before Bastianini tried a move but ran wide, leaving Martin and Di Giannantonio side by side in the final corner, with Martin winning the sprint to the line by just 0.023s to complete the rostrum.
But four and a half seconds earlier Fenati had taken his first win of the season in style.
Bastianini, Bulega and Guevara came home from fourth to sixth, with McPhee beating key championship rival Mir to seventh and Oettl the final rider in the second group, while Darryn Binder (KTM) rounded out the top 10.