Dario Franchitti became the second driver to lead an IndyCar Series race from flag to flag on Sunday and closed ground in the tight fight for the IndyCar Series championship.

Franchitti won the Indy Grand Prix of Sonoma at Infineon Raceway by just 0.25 seconds. It was his fourth win of the season and the 12th of his IndyCar Series career.

"It was a good weekend for Target Chip Ganassi Racing," said Franchitti. "The Target cars were pretty good. On the red Firestone tyres they were very good. Qualifying up front allowed us to control the pace of the race and go just as fast as we used to go and that really helped us."

Ryan Briscoe took the runners-up spot and that gave him the championship points lead - four points up Franchitti. It's the 13th time the championship points' lead has changed in the 14 races this season.

"I got into a pretty big deal with Dario's rear wing there today. That was pretty much the story of my race," Briscoe noted. "I was pretty conservative on the fuel during that first stint and I actually thought I was going to be able to get him by going a lap further and I was surprised to see that he went a lap further than me.

"That's something we need to work on for this track, fuel mileage, but the Team Penske car was pretty good today. I think if I would have had clean air I would have been quicker than Dario. With dirty air there wasn't much I could do.

"Unfortunately, it is a really tough track to pass on if the guy in front of you doesn't make mistakes. I don't think that Dario made one today, but congratulations to him and his team. Team Penske did an awesome job and had great pit stops. We're leading the championship so hopefully we can hang onto it."

Dreyer & Reinbold Racing rookie Mike Conway rounded out the podium places - his best finish in the IndyCar Series. His previous best was sixth at Watkins Glen earlier this year

"It was good," Conway reflected. "In the beginning, we got hit from behind and I got a puncture in my rear tyre. I thought my race was finished. I just kept pushing all the way though and just kept moving forward, and I kept setting quick times.

"Towards the end, I knew I might be able to get past the guys in front. The Tran Systems car was really good today. If we had a few more laps, it would have been interesting to see if I could get past those guys."

Mario Moraes was next up in fourth - and like Conway it was also a career best finish: "The last two weeks have been really tough for me, but it felt good to get back into the car and have a good race," Moraes stated.

"The KV Racing Technology team did a great job today, in fact, for the whole weekend. In qualifying, we had a little problem, but we went back to our original plan. In morning warm-up, we thought the #5 Azul/Votorantim car was fast, and I think moving up ten places in the race today proved it. I would like to thank the whole KVRT crew again for everything and also the fans for all the support over the last two weeks."

Further down the order Hideki Mutoh was fifth for the second race in succession, although he was passed by both Conway and Moraes on lap 73.

"If I was able to keep the third position, it would've been a great finish, but the Formula Dream car was fantastic," Mutoh noted. "Our pit stop was great, as well, so we were able to pass Helio. I really would like to thank all the Andretti Green people for their great support and the fans here. I enjoyed the race today, and am looking forward to next week's race at Chicagoland."

Of the rest Oriol Servia came in sixth, followed by Justin Wilson, Tony Kanaan and Raphael Matos. Robert Doorrnbos completed the top ten.

"What a day," said Doornbos. "It's such a long day when the car is not competitive. I'm sorry for the guys behind me, I was just holding them up in the beginning, but I was just doing everything I could to stay on the track. Obviously we had a mega start. We got about eight positions at the start, so we were running in sixth place. That was good. But the pace was just not there."

Meanwhile Scott Dixon, who led the points' coming into this event and who started from tenth, ended up 13th, after he got caught up in the first-lap jumble that entangled seven mid-pack cars in Turn 2.

Though he could continue after the 'hit and run' and weaved from 15th to 10th, he was bumped back to 13th on the white flag lap after an incident with Marco Andretti. Andretti was later penalised by officials for 'avoidable contact' and was placed behind Ed Carpenter, Dan Wheldon and Dixon, in 11th, 12th, and 13th respectively.

Dixon, who now drops to third in the championship standings, 20 points behind Briscoe, was philosophical about his weekend.

"It was a tough race," he stated. "Every thing we tried to do. We tried to catch a yellow. We pitted early to see if it could vault us up, and we kept coming out in the same position, racing with TK and Marco and we got into a bit of a mix-up at the end.

"Marco got into the back of me and spun me around. He came up and apologised. He definitely didn't do it on purpose. It was just one of those days. That's racing. I'm glad to move on and get out of here.

"It can still switch big time in terms of the points. That's what we've got to look at. We need to be consistent in the last three races - and hopefully, they can have a bit of a blunder. But the Target team can win the last three races and hopefully we can do it and come home with another championship."