Suzuki's Mat Mladin beat teammate Ben Spies in the second Superbike race at Fontana, winning by 0.035 seconds in a tight battle. Eric Bostrom took third, his second podium of the year for Yamaha.
Mladin led the early going, pushing hard to eek out a 2.5 second lead. Spies rebounded, closing the gap and taking the point briefly on lap 23 after Mladin made a mistake.
But Mladin reversed the trend and retook the lead in traffic soon after he had surrendered it.
The last five laps saw Spies circulate right on Mladin's tail. Spies was unable to formulate a move to get by Mladin. The race to the flag saw Mladin take his 54th career AMA Superbike victory.
"We found something about ten o'clock last night in the truck," said Mladin. "It was good enough, but only just."
Spies currently leads Superbike points 173 to 164 over Mladin.
Suzuki's Tommy Hayden had a good race and moved to fourth place, past the Hondas. Jake Zemke was the quicker of the Honda runners this weekend.
The Kawasakis of Roger Hayden and Jamie Hacking moved past Aaron Yates of the Jordan Suzuki team during the race to take seventh and eighth.
NFS Honda's Doug Chandler finished 11th, the three-time AMA Superbike champ's best race of the year.