Stewart dominated the opening round of the U.S. Open Supercross race at the MGM Grand Garden by winning the pole, getting the holeshot award and running away with the 20-lap feature.

Stewart, riding for the L&M racing team that fielded Yamahas for Chad Reed last year, was the fastest in the 14-bike field but received an assist when Reed's new Suzuki broke on the first lap.

Reed, the reigning Supercross season champion, battled frame to frame with Stewart and others for the $5,000 holeshot bonus that goes to the first rider to clear the course's second turn.

"I never touched him," Stewart said of making contact with Reed. "We were all going into the first turn. Chad came in and I gassed it. Everyone was racing for that line and I sneaked through."

Stewart took the line by inches, but in the rough-and-tumble start something on Reed's bike was damaged. He slowed to the back and didn't complete the first lap.

Stewart got another break -- as if he needed any -- when his three closest pursuers about six seconds behind crashed near the end of the 14th lap.

From there, Stewart could have carried his Yamaha to victory, which paid $35,000. On the night, he also won $10,000 for winning the pole as well as the $5,000 for getting the holeshot.

Stewart's winning margin was 21.9 seconds over runner-up Ivan Tedesco on a Honda.

Josh Hill was third on a Yamaha, Justin Brayton fourth on a KTM and Ryan Dungey fifth on a Suzuki.

"I'm stoked to start out this way," Stewart said. "(The new Yamaha) is different, but different in a good way."

Obviously.

If Stewart matches his effort tonight, he will receive a $150,000 bonus and leave the MGM with $250,000.

• NOTES -- When the second round begins at 7 p.m. today, riders will race a reconfigured course. ... Reigning Open champion Grant Langston was unable to compete after undergoing surgery last week to begin treatments for a tumor in his left eye. ... In other races Friday, Damon Bradshaw beat Jeff Matiasevich in the Legends Race and Austin Politelli won the 85cc Invitational.

Contact reporter Jeff Wolf at jwolf@reviewjournal.com or 702-383-0247.