Ken Roczen made it two for two in Anaheim by winning the supercross race at Angel Stadium on Saturday night.
The Suzuki rider also won the season opener at Angel Stadium two weeks ago, then finished second to Eli Tomac last weekend in Phoenix.
Former champion Ryan Dungey finished second Saturday night, 5.2 seconds behind Roczen, in the 20-lap main event. Tomac finished third in the 22-rider race in front of announced crowd of 40,718.
"What an awesome race, we fought hard the whole way," Roczen said.
The Monster Energy AMA Supercross Series is holding three of its first five races in Anaheim this year.
Supercross is the stadium version of off-road motorcycle racing, or motocross, and the series uses about 600 truckloads of dirt to lay out different courses of curves, hills and jumps at every stadium it visits.
The track configuration on the Angel Stadium infield Saturday night also included a seldom-used feature: A bridge nearly two stories high that the riders raced both over and under.
Kawasaki's Ryan Villopoto had won the supercross championship the last four years but he's racing overseas this season. So the sport this year will crown a different champion for the first time since Dungey won the title in 2010.
Yamaha rider Cooper Webb of Newport, N.C., won the 15-lap main event in the sport's second-level 250SX series.
Webb had just pulled alongside Tyler Bowers of Corona for the lead on the final lap when Bowers' Kawasaki bobbled and spun, enabling Webb to reach the finish line unchallenged. Bowers finished second.
Jessy Nelson, who won the 250SX race on his KTM bike in the first Anaheim race this year, led early but crashed on the seventh lap and finished sixth.
The supercross series visits Oakland next week for the fourth race on the series' 17-race schedule and then returns to Angel Stadium for the third and final time Jan. 31.