Ryan Briscoe is the winner of the GoPro IndyCar Grand Prix 2012 at Sonoma Raceway. He took the lead in the 2.31-mile, 12-turn course ahead of second-place driver and defending champion Will Power, with Dario Franchitti in third place.
Briscoe last won an IndyCar race in Texas in 2010.
"It's big," he said of the event in Sonoma this past weekend. "I wasn't sure I was ever going to win again."
Power, defending his two Grand Prix wins at Sonoma, is Briscoe's Team Penske teammate.
"It was fun at the end there with some pressure from Will," Briscoe said.
Briscoe had finished second, third and fourth at Sonoma in the past four years.
He held off Power on a pair of late restarts and won the event by 0.4408 of a second. He became the seventh different winner in 13 IZOD IndyCar Series races this season.
Briscoe gained the lead on a pit stop sequence on Lap 65 when he hit the blend line ahead of Power, who had pitted a lap earlier but was caught behind traffic during the first full-course caution in more than 2½ races.
Power, who clinched the Mario Andretti Road Course Trophy for the third consecutive year, increased his championship points lead from five to 36 over Ryan Hunter-Reay of Andretti Autosport with two races remaining.
Hunter-Reay was running third behind the Team Penske duo when the No. 28 Team DHL/Sun Drop Citrus Soda car was bumped from behind by the No. 98 Barracuda Racing car driven by Alex Tagliani in Turn 7 on Lap 75 and stalled. The turn of events dropped Hunter-Reay to an 18th-place finish.
Dario Franchitti finished third and Rubens Barrichello posted a season-high fourth place after starting 11th. Graham Rahal placed fifth and Helio Castroneves was sixth. Simon Pagenaud clinched the Sunoco Rookie of the Year award with a seventh-place finish.
The top eight drivers are mathematically eligible for the championship heading to the Grand Prix of Baltimore on Sept. 2.
Derek Wilson and Julie Pendray contributed to this report.