Helio Castroneves had never previously led a lap at Infineon Raceway, and had gone some 29 races without being able to enjoy his familiar fence-climbing 'spiderman' celebration, but put both right on Sunday afternoon in Sonoma.

Echoing the sort of resolve that saw Sam Hornish Jr win for Penske after its facilities had been badly hit by flooding a couple of seasons back, the Brazilian shrugged off this week's transporter fire to convert pole position into a first victory since St Petersburg in 2007, claiming the bonus point for most laps led for good measure along the way.

To make things even better for Penske, Ryan Briscoe backed Castroneves up in second place, the two distinctive red-and-white machines reprising the 1-2 result from qualifying as Castroneves made sizeable inroads into Scott Dixon's championship lead.

In a race largely decided by pit strategy, Castroneves led Briscoe away at the start of the 80 laps, returning to the front each time the early stoppers had to call in for more fuel and new rubber.

Vitor Meira, Buddy Rice and Dan Wheldon were the first to chance their arm by switching to an alternative gameplan, but otehrs followed the final results showed a mix of those to take the gamble and those, like Briscoe, Tony Kanaan and Danica Patrick, who decided to stick with convention and hold on for as long as possible.

With just one yellow, for the hapless Marty Roth's spin on lap 16, the benefit of stopping as early as Wheldon, Meira and co had done was negated, with each needing to make a third fuel stop before the chequer came out. After that, it became a question of pace and positioning that determined who finished where as the strategies collided.

Castroneves led until the yellow prompted the first rush for the pits, handing the lead to his team-mate for the next ten laps. The Australian's need for fuel promoted leading rookie Ernesto Viso to the front of the pack, the Venezuelan having stopped amongst the early batch on lap 13.

Viso enjoyed eight laps out front before his strategy handed the initiave back to Castroneves on lap 37, the Brazilian resuming with Briscoe, Dixon, Justin Wilson - up from seventh on the grid - Will Power, Oriol Servia and Kanaan in his wake. Stopping when he did, however, allowed the poleman to open out an eleven-second gap to his Penske partner and a crucial 13 to title rival Dixon.

Briscoe retook the lead when Castroneves next pitted on lap 44, but the Brazilian rejoined this time in fourth spot, behind Kanaan, ande was able to quickly cycle back to the front over the next ten tours. It was clear though that, with a tank lasting only around 26 laps, a third stop would be required for Castroneves to make the chequer, while his main rivals could run to the finish after their second.

When Kanaan pitted on lap 54, Castroneves returned to the front and again set about building the sort of advantage that would allow him to have the best chance of victory. He had only three laps, however, pitting for a top-up on lap 57 and allowing Viso another brief moment of glory, but was back in front when the Venezuelan peeled off two tours later and then reeled off the laps the the flag, eventually coming home just over five seconds clear of Briscoe.

Like the Australian, Kanaan made his two stops work to his advantage, coming home third, but Andretti Green team-mate Patrick wasn't quite able to follow suit, allowing the three-stopping Wheldon - up from 16th on the grid - to comfortably pip her to fourth, while Vison came home sixth, his best result since finding the podium on the streets of St Petersburg in April.

Castroneves' win aside, however, perhaps the biggest story was Dixon's slide down the order, the Kiwi's three-stop strategy not working out as well as either his main championship rival's, or Ganassi team-mate Wheldon's. Dixon, who could have clinched the crown had results gone his way in California, looked set to finish 14th before a late clash between Servia and Mario Dominguez handed him two vital spots.

The Indy 500 winner arrived at Infineon with a comfortable 78-point cushion over Castroneves, but now heads to the Penske-owned Belle Isle Raceway in Detroit with just 43 markers separating him from the Brazilian. A similar outcome next weekend could set up an intriguing showdown on the oval at Chicagoland.

In Dixon's rare and unexpected absence from the top order, Meira, Graham Rahal, Wilson and the ever-improving Mario Moraes rounded out the top ten, with Rice also coming home ahead of the Kiwi.

There was also disappointment for KV Racing Technology duo Servia and Power, both of whom had started and run in the top six before fading away. Servia's drop down the order was relatively slow and undramatic, a brush with Dixon as he exited the pits and the late clash with Dominguez aside, but Power clearly had problems on his vivid yellow-and-green machine as he persistently took to the escape road at the chicane.

After three such transgressions, the stewards took a dim view of his antics and called him for a drive-thru' penalty, but that failed to prevent a repeat and the fifth excursion eventually proved Power's undoing as he collected the tyre stacks designed to provide an obstacle within the obstacle and retired three laps from home.

Although classified, Power joined Tomas Scheckter on the sidelines, the South African making a rare appearance with Luczo Dragon but succumbing to mechanical problems just shy of two-thirds distance. He will be encouraged, however, by the team's decision to race in Detroit next weekend.

Watkins Glen stars Ryan Hunter-Reay and Darren Manning never really featured at Infineon, the American being tapped into an early spin by Wilson and eventually coming home just five places ahead of Manning, in 18th.

At the end of a week of drama, and weekend of domination, there was only one disappointment for Castroneves, who found that there were no catchfence on which to perform his celebration.

Not wanting to be defeated, however, the Brazilian scaled a small wall and railing, to the delight of the small crowd of fans who promptly engulfed him, before returning to pit-lane to pay tribute to the crew that had turned tragedy into triumph.