(Reuters) - Reigning MotoGP world champion Australian Casey Stoner has claimed the U.S. Grand Prix at Laguna Seca on Sunday, besting Spain's championship leader Jorge Lorenzo by almost three and a half seconds.

Stoner defended his victory from 2011 on the California course with his Repsol Honda teammate Dani Pedrosa of Spain claiming third place, 7.633 seconds behind.

Nicky Hayden was the best of the locals, finishing sixth, 26.902 seconds off the pace.

Stoner started second on the grid behind Lorenzo and after dropping to third early he set about chasing down the Spanish pair.

He took down Pedrosa on lap two of 32 before passing his main rival with 11 laps to go with a crisp move down the main straight.

Stoner was the only one of the front-runners to start on softer option rear tires, a tactical masterstroke in the end.

"It was tactical from the start we went on the softer option which nobody decided to go on so I wanted to go in front from the outset," Stoner said.

"I bided my time, hunted Jorge down and in the end went past."

Lorenzo, who has finished inside the top two in all nine of his 2012 races, increased his championship lead to 23 points over Pedrosa, with Stoner now 32 points adrift in third as he chases a third world title before his impending retirement at the end of the season.

(Reporting by Ben Everill in Los Angeles; Editing by Ed Lane)