Australian Honda rider Casey Stoner stretched his lead atop the MotoGP standings with superb victory in the US Grand Prix at Laguna Seca Raceway.

Stoner surged past Spain's Jorge Lorenzo on the 27th of 32 laps on the technically demanding circuit to claim the victory and take his points total to 193, 20 more than defending world champion Lorenzo who had started from pole despite a spectacular crash in practice on Saturday.

Stoner's Respol Honda teammate Dani Pedrosa of Spain was third.

Stoner won in 43min 52.145sec, more than five seconds ahead of Lorenzo.

"We felt good, really good, at the end," said Stoner. "It's really good to come back with a race like this and show everybody that we can still win."

The Aussie notched his fifth victory of the season, but hadn't won in three races since a victory at Silverstone.

The 25-year-old captured the 28th MotoGP win of his career and turned the tables on Lorenzo, who beat him here last year.

Lorenzo got off to a flying start and led much of the race before Stoner got past him and inexorably pulled away to leave the Spaniard 5.634sec adrift.

After his crash, which sent him airborne and left him bruised and sore, Lorenzo was happy with a runner-up finish.

"I'm lucky to be in the second position this weekend, because after the crash yesterday morning, in the first moments I thought it wasn't possible to take part in the race," he said.

"So after qualifying I really hoped to fight for the victory till the end. But sometimes expectations are not the reality, and today Casey was faster than us, especially at the end.

"He had something more than we had.

"Also my physical condition was not so perfect, so together it made us quite slow at the end."

Pedrosa finished right where he started on the grid in third, more than nine seconds off the lead.

Italy's Respol Honda rider Andrea Dovizioso finished fifth behind Lorenzo's teammate Ben Spies of the United States. That was good enough to keep Dovizioso third in the standings with 143 points.

The Ducatis of Valentino Rossi and Nicky Hayden finished sixth and seventh. Alvaro Bautista had pursued them until he crashed his Suzuki. Italy's Marco Simoncelli and Britain's Cal Crutchlow also failed to finish.

France's Randy de Puniet didn't start after suffering two broken vertebrae and a suspected broken pelvis when he crashed his Ducati in qualifying on Saturday.

Despite nabbing a place on the front row of the starting grid, Stoner had predicted he might struggle in the race. A breakthrough in the morning warm-up, however, had him feeling more optimistic.

"To be honest it was the most relaxed I've been before a race in a long time," Stoner said. "We've had a really difficult weekend, but this morning in the warm-up we found something and thought we could run with these guys.

"At the start of the race I really struggled. I was patient, I was quiet, I knew that they weren't going to pull away and I still had something left.

"Lap by lap, when the fuel went out, it just got better and better," he added.

First he set his sights on teammate Pedrosa.

"I saw Dani struggling a little bit and decided to go past him because we were losing time to Jorge," Stoner said.

"Then once I caught Jorge, I wanted to stay behind to see what was going on. Then we knew we had some more pace than what Jorge was able to run and we decided to go to the front and see what happened."