San Francisco Frontiers - Vinales wins MotoGP Grand Prix of the Americas sprint

The Spaniard, who smashed the lap record in qualifying, built a lead of more than a second on his Aprilia and rode serenely to the line as behind him three compatriots fought for the other podium places.

"I want to keep going. The level was amazing," said Vinales, punching the air, before stepping up to the podium.

Vinales completed the 10 laps in 20 minutes 27.825 seconds, 2.294sec ahead of seven-times winner at the Circuit of the Americas, Marc Marquez on a Gresini Ducati.

Jorge Martin increased his championship lead with third on a Pramac Ducati, 4.399sec behind the winner while teenage rookie Pedro Acosta, on a GasGas, was fourth.

Marquez said he was not entirely happy with his performance.

"Was a bit harder than I expected," he said.

"In the first lap I was quite strong but then I start to feel not so good. Then I decide to wait for my moment. I was in front of the group. When Pedro attacked me, I said 'OK, now is the time'. I was half a second faster in the next lap and then I opened a gap."

Martin crashed twice in morning qualifying and started from the second row of the grid.

"This morning we took crashes," he said, adding that he too had had problems during the race.

"Today was a tough race. I struggled quite a lot in the middle of the race with some issues but to finish on the podium is amazing. We are super-constant. This is the most important thing."

The other Aprilia rider, Spaniard Aleix Espargaro, was fifth with Italian Enea Bastianini sixth for factory Ducati.

Italian double reigning world champion Francesco Bagnaia, who performed an unintended wheelie at the start and lost momentum, was eighth.

Martin moved to 67 points in the championship, 24 ahead of Bastianini. South African Brad Binder, who was 12th on a KTM, is another point behind.

The battle resumes on Sunday in the 20-lap main race

Marquez said he needed to handle some of the corners better.

"Let's see that turn one where we can improve to keep up with Vinales," he said

Martin ws also trying to work out how to keep pace with Vinales.

"Tomorrow let's go for a better race," he said.

B.Turner--SFF