Langston, who entered the season finale needing to hold off his three nearest competitors for a first premier-class crown, turned in a championship-winning 1-3 performance en route to his third-straight overall win and title glory.
"It's definitely a great feeling to win this championship," said Langston, winner of the 2003 AMA 125cc Motocross championship and 2005 and 2006 AMA 125cc Supercross titles. "I think it was just five or six races ago that I thought I didn't have a chance [at winning the title]. Every week I kept chipping away. The championship was a like a carrot being dangled in front of me. Once I could see the carrot I got on a roll."
KTM's Mike Alessi finished 2-2 for second overall on the day, and in the championship, while Kevin Windham was third at Glen Helen with 5-1 results. Another Honda rider, Andrew Short, took third in the series, with Tim Ferry the top Kawasaki rider - following title favourite James Stewarts' early end to the season - in fourth. Windham completed the championship top five ahead of part-time racer Carmichael and the injured Stewart.
In the Lites class, Ben Townley - who entered the event trailing by 19 points - picked up his sixth overall win of the season with a 1-2 moto finish, but it wasn't enough to keep reigning champion Ryan Villopoto (1-2) from walking away with his second consecutive title. Another Pro Circuit Kawasaki rider, Bret Metcalfe, was third overall after a 3-3 finish in the motos.
"I always heard that it was harder to back it up," said 19-year old Villopoto, referring to defending his title. "Mitch [Payton, team manager] said he hasn't seen two guys go at this hard. Ben and I went at it every weekend. It was definitely harder than last year."