Will Power a convincing winner at Indy Grand Prix of Sonoma

Reporting from Sonoma, Calif. — 

When IndyCar team owner Roger Penske announced last November that he would give Will Power a full-time ride this season, Penske asserted that Power could be “a legitimate championship contender.”

Anyone doubting Penske had cause. Power at the time was recuperating from a broken back suffered in a practice crash at Infineon Raceway here last summer, after driving only a handful of races for Penske earlier in the season.

But the Australian driver has proved Penske was right.

One year after being airlifted from the track following his crash, Power drove to a dominating win Sunday at this year’s Indy Grand Prix of Sonoma and widened his lead in the championship standings in the Izod IndyCar Series.

Starting on the pole, Power led all but two of the race’s 75 laps en route to his series-high fifth win of the season and, following a restart with only six laps remaining, held off charging Scott Dixon and Dario Franchitti, the teammates at Target Chip Ganassi Racing who finished second and third, respectively.

Power’s two Penske teammates, Ryan Briscoe and Helio Castroneves, were fourth and fifth, respectively.

“I watched this race from the hospital bed last year,” Power said after celebrating in Victory Lane. “I said it all year, I’m coming back to win this thing because I thought this track owes me after what happened.

“It’s unreal, what a perfect weekend,” he said, and thanked Penske “for having faith in me to come back and be fast again” after his injury. “I want to win the championship.”

But Power’s quest for the title won’t be easy. The final four races of the season are all on oval tracks, as opposed to curvy road courses such as Infineon, and Power, 29, has less experience on ovals than Dixon, Franchitti and others.

In the four previous oval races this season, Power finished no better than fifth.

Nonetheless, Power now has a 59-point lead over Franchitti in the standings and a 95-point lead over third-place Dixon, both of whom already have two championships apiece. Franchitti is the reigning champion.

“We just weren’t quick enough to catch Will” on the 2.3-mile, 12-turn Infineon course, where passing is always difficult, Franchitti said. “We did the best with what we had today.”

Added Dixon: “I gave it all I could on the [final] restart, I was trying to stick my nose in wherever I could. I tried to apply as much pressure as possible to force [Power] into a mistake.”

But Dixon said, “I just couldn’t even get close enough him to have a look. He was definitely hooked up.”

Power, who easily laughs about the one-liners that his name evokes — his formal name is William — was an accomplished road-racing driver in the former Champ Car World Series.

But when that series was absorbed into the IndyCar series in 2008, Power wasn’t immediately sure he would secure an IndyCar ride until Penske came calling.

“At the end of 2008 I was almost ready to go home to Australia,” Power said. “I never would have known what my potential was.”

And Franchitti cautioned against discounting Power’s ability to win the IndyCar title. “People are writing him off because of his lack of experience on ovals, but he’ll be right up there,” Franchitti said. “We’ll have to do a better job.”

The race effectively started on the fourth lap because of a crash involving former Indianapolis 500 winner Dan Wheldon that occurred just as he was taking the green flag in the 12th position in the 25-car field. He was unhurt, but that put the race under a three-lap caution period before racing resumed.

There were several other instances of cars making slight contact but no other major wrecks. One of the last accidents involved rookie Bertrand Baguette that produced the final restart with six laps left.

james.peltz@latimes.com