The first upset came early in the evening, when San Bernardino's Charlie Venegas finished last in his first heat race.
But Venegas called it "a blessing in disguise," an opportunity to race without pressure.
And that's what Venegas did.
Venegas didn't lose another heat race, semifinal or main event on Saturday, winning the Coors Light U.S. National Speedway Championship at the Orange County Fairgrounds.
Venegas, 33, outlasted Monrovia's Josh Larsen and the 1992 winner, third-place Chris Manchester of Upland.
Dukie Ermolenko of Cypress took fourth and Bobby Schwartz of Costa Mesa was fifth in the four-lap main event.
"This means everything to a speedway rider to win here even though it's not AMA [American Motorcycle Assn.-sanctioned]," said Venegas, a 13-year veteran at the 31-year-old venue. "I eat, breathe, sleep . . . everything I do is this."
Venegas, riding a Jawa, survived two restarts in the final after crashes took out other riders. But all the action took place behind him because his starts from Gate 1 gave him the lead each time.
"He's notorious for his flyer starts," Larsen said. "The rule they were trying to enforce was anticipating the starts, but he nailed it. It was an awesome start. He ducked under the tapes and was gone. He had the starts down. He could almost read [the starter's] mind."
In the U.S. Championship format, each rider rode four heat races without facing the same rider twice. The top 10 riders advanced to the semifinals.
There was a runoff between Brea's Shawn McConnell, Ojai's Eddie Castro and Forresthill's Bart Bast for the final two spots because they were tied after four rounds of heat racing. Castro won the runoff and Bast took second. The top two finishers from each semifinal advanced to the final, along with the winner of the Last Chance Qualifier, Larsen, who was the highest scoring rider after the heat events.
Venegas had dominated the season standings at Costa Mesa, but lost by one point to Ermolenko on the final night of the series. Instead, Venegas was in Auburn that night winning the state championship.
Schwartz was trying to win his first national title since 1989, but was taken out on the last lap by Manchester in the battle for third place. Ermolenko was trying to join his brother, Sam, as a national champion. He was involved in both crashes that forced restarts, with Schwartz, then with Larsen. The latter forced Ermolenko to be penalized 20 yards for the final, and he passed Schwartz when Schwartz fell.
Larsen scored 11 of a possible 12 points through four rounds. Venegas and Riverside's Gary Hicks, who finished behind Schwartz and Mike Faria in a heat race that brought the crowd to its feet, were the only riders to win three of their four heats. In the semifinal, Hicks' chain broke; he finished last, and did not advance to the Last Chance Qualifier.