SONOMA — Mat Mladin kicked it into high gear on Saturday to take the weekend’s first Superbike win by the season’s largest margin of victory, 19.135 seconds, ahead of Yoshimura Suzuki teammate Ben Spies.

The win was the Australian rider’s fourth of the season and puts his career total at 55 to lead all Superbike riders.

“It was a good race for us,” Mladin said, adding he’s not positive as to how he managed such an amazing lead over the 28 laps. “We got a good start and we just put our head down and tried to go as quick as possible. It got breezy there around halfway through the race. I lost a little bit of rhythm, but it seems like everybody did the same. It was a good day for us and hopefully we’ll get another win (Sunday).”

Mladin beat Spies at Virginia last August by 19.5 seconds, a day after Spies broke his right hand during qualifying.

“You know, sometimes things change and I don’t think I forgot how to ride a motorcycle,” Spies said. “I rode as hard as I could the whole race and, I can’t put my finger on it, but it wasn’t the same.”

Mladin started the race as the second-fastest qualifier but jumped ahead of pole-winner Spies from the gate when Spies gunned it too hard and wheelied at the start line. Spies’ second-place finish and pole point keeps him first in the points race with 206 and Mladin stays in second, just five points behind. Mladin broke Spies’ 2006 track race record, finishing the race in 45 minutes, 7.101 seconds.

“We’re just experimenting with some things,” Spies said about his sketchy start. “We know exactly what it is. Sometimes we get really good starts and sometimes they’re just OK. It looked horrendous but was still good enough to be second out of the gate.

“He set a blistering pace we couldn’t match. There was no way I could run that pace today and I knew that at the start. It wasn’t comfortable running that pace at all.”

Mladin added, “We had things set up pretty good here. We were confident that we could do those lap times.”

The teammates both went into the dirt at Turn 1 of their second lap with Spies riding wide right and kicking up quite a bit of dust. Spies said he locked up the tire and “motocrossed it a bit” but added that it didn’t affect the outcome of the race.

Spies went down on his final qualifying lap on Friday on Turn 9c and though he was fine, his Superbike was not. He ran his backup bike during Saturday’s qualifying and race and was quick to rule out the backup bike being a factor in his second-place finish.

Mladin jumped ahead by three seconds by the end of the third lap and continued to increase his lead every single lap with two exceptions. He ran into some traffic on Lap 16 when he closed in on Petaluma native Eric Bostrom, who pitted early on for a new rear tire. Mladin’s lead was cut from 6.519 to 6.125 to 6.054 before he passed Bostrom and continued to pull ahead.

Miguel Duhamel (Honda) finished third for the third time this season and third straight time at Infineon Raceway. He stays in third place in the points race with 170 – 36 behind Spies. Duhamel started seventh, after gaining one position in Saturday’s qualifying, but quickly leapt to fourth behind Jason Disalvo (Yamaha). Duhamel passed Disalvo on Lap 15.

“I got a decent start and just followed Jason and he was riding well,” Duhamel said. “I was a little strong here and there, and when I finally got by him, I put a gap on him and I started focusing a little bit on Ben. I just tried to keep a good pace and keep him honest in case something went wrong.”

Despite being passed halfway through the race, Disalvo was more than happy with his Superbike career-best, fourth-place finish.

“Awesome! I’m really stoked to finish fourth,” said Disalvo, who qualified sixth. “The Yamaha R-1 was fantastic. We keep getting better and better each time out.”

Jake Zemke (Honda), Roger Lee Hayden (Kawasaki), Tommy Hayden (Suzuki), Jamie Hacking (Kawasaki), James Ellison (Honda) and Matt Lynn (MV Augusta) rounded out the Top 10 finishers.

Today’s main events start at 1:10 p.m. for Superstock, 2 p.m. for Supersport and 3 p.m. for Superbike’s Race 2.