Will Power claimed his third win of the season at California's Auto Club Speedway as Scott Dixon secured his third IZOD IndyCar title on Saturday night, defeating Helio Catroneves in an action packed race of attrition that ended with only nine cars, five on the lead lap, still running at the end.
The Kiwi went into the MAVTV 500 Presented by Lucas Oil with a 25 point advantage over title rival Castroneves after an upturn in form in the second half of the season saw him win three races.
The front row of the grid was locked out by the Penske team with Castroneves right in the middle in second place. Dixon started in seventh.
Castroneves looked set to secure the title early on after taking the race lead after a cation period casued by a wreck between Pippa Mann and Sebastian Saavedra.
Castroneves exchanged the lead with Tony Kanaan and Marco Andretti, who ran at the front for most of the race before eventually finishing seventh, two laps down after suffering with engine problems.
Another caution as a result of a major wreck which wiped out several drivers - including Justin Wilson who was transported to a local hospital - allowed Castroneves to snatch the lead back during the pitstops.
He wasn't to hold the lead for long though, dropping down to fourth as the race resumed with 53 to go after AJ Allmendinger brought out another caution for wrecking in turn two. It was Dixon who led as the field went to green on lap 197.
Alex Tagliani, subbing for the injured Dario Franchitti, brought out yet another caution on lap 209 after spinning on turn 2. During that period Helio Castroneves' evening went from bad to worse as he served a drive through penalty for entering a closed pit, ending his championship hopes.
Once he eventually pitted properly, Castroneves returned to the track in ninth place with Dixon third.
After the field went back to green Dixon launched back into the lead with 34 laps to go whilst Castroneves rallied back to third before briefly moving into the lead a lap later, battling wheel to wheel with Charlie Kimball.
Contact with James Hichcliffe provided another setback for Castroneves as front wing damage put the Brazilian a lap down just as he had fought back into a position to battle for the championship once more.
There was yet more twists to the tale though as Scott Dixon pitted with 20 laps to go to fix an overheating issue. Meanwhile Sebastien Bourdais crashed out of the lead bringing out another caution.
Dixon had to pit again during the caution to change tyres and to further resolve the overheating problem. He stayed ahead of Castroneves though, albeit it only by one postion whilst Castroneves remained a lap down.
Even though the race resumed with 13 laps to go, one lap later Charlie Kimball's engine expired leaving Dixon as the only Ganassi runner left fighting.
He wouldn't need the support of his team mates though as with Castroneves staying a lap down, Dixon had done enough to win the championship as Will Power charged away to win the race.
Despite Dixon winning the championship for Honda, it was Chevrolet who won the manufacturers championship for the second consecutive season.
Helio Castroneves finished runner up for the third time whilst Simon Pagenaud, Marco Andretti and Justin Wilson had their best seasons to date finishing third, fifth and sixth respectively in the points. Will Power broke up that group taking fourth in the points table.