Ben Spies' hopes of a home US MotoGP podium effectively ended within the first 500 feet of Sunday's Laguna Seca race, when he dropped from fourth to seventh.

The Factory Yamaha rider blamed the decline on a lack of power, and it meant Spies spent the first two laps stuck behind Valentino Rossi.

"I got a really good start but going uphill to the steep part of the track basically we didn't have enough power," explained Spies. "I got stuck behind Valentino, I tried to get around as quick as I could but he's really good on the brakes so it was pretty tough but I did the best I could."

By the time Spies got past the Italian, the riders ahead had already pulled a gap.

Spies was promoted to fifth when Marco Simoncelli crashed, then closed a gap of over five seconds to take fourth from Andrea Dovizioso with just three laps to go.

"Once we got around Rossi it was quite a big gap to Dovizioso, but I just kept my head down and kept going," said the Texan. "I'm happy we were able to track him down and get fourth. It was a really good race for us it just got spoilt in the first 500 feet.

"I would have liked to have been on the podium as I think we had a package to fight with Dani, I guess that's racing and I gave it 100% as always," added the Assen winner.

Dovizioso also felt he could have done better.

"I'm disappointed because today we had the speed to fight for a good result, in fact I lapped two tenths behind the fastest lap, but I couldn't be consistent," said the Repsol Honda rider.

"I lost the battle with Spies and this is the first time I've lost a battle this year."