FONTANA, Calif. (AP) Will Power raced with his head instead of his gut. Only a catastrophe was likely to derail his IndyCar Series championship, and the Australian knew he had to throttle the aggression that has made his career - and occasionally wrecked it.
Yet after Power moved patiently and safely through the Fontana field, a restart gave him a chance to seize the lead, if only for a few laps.
Power couldn't resist. With one last daredevil move, he pulled in front for just long enough to ensure he wouldn't back into his long-awaited title.
''On that restart, I thought, `I've got to lead a lap and not go backward,''' Power said. ''That was the key to the race. No mistakes. Stay on top of the car. ... It's such an emotional moment for me. I'm so grateful to have this opportunity.''
Power won his first series championship Saturday night, finishing ninth in the final race before raising the Astor Cup for the first time in a career filled with agonizing misses.
Tony Kanaan won the 500-mile, double-points race under the lights at Fontana for his first victory of the season, but Power easily preserved his healthy points lead over second-place teammate Helio Castroneves to wrap up Team Penske's first IndyCar title since 2006.
Power felt enormous stress, but didn't show it.
''That was one of the hardest races ever,'' Power said. ''Oh my God, I was crying. It just went on and on. I slowly made up position, and it was great.''
Starting from the back after a poor qualifying run, Power patiently picked his way through the field to the front. After that restart with 62 laps to go, the Australian roared into the lead with authority before falling back into a safe parade to the finish.
Kanaan earned his first victory for his new Target Chip Ganassi Racing team, and the 17th of his career. The Brazilian is the 11th driver to win a race this season, tying the North American open-wheel record set in CART in 2000 and 2001.
But the season belongs to Power, who showed much more relief than elation while overcoming still-fresh memories of heartbreak. He led the IndyCar points standings heading into the final race in 2010 and 2012, and he led with two races left in 2011 - but he failed to claim the title each time, a fact that loomed in his mind for 250 laps at Fontana.
''I'm so mentally exhausted right now,'' Power said. ''My hands are numb from holding onto the wheel so tight.''
Power's mother and wife watched from the pit area, sometimes turning their heads away in nervousness as the laps wound down and the specter of Power's past loomed.
They didn't need to worry: The pride of Toowoomba, Australia, finally is a champion.
Roger Penske's team completed a dynamic season by claiming three of the top four spots in the overall standings, with fourth place wrapped up by Juan Pablo Montoya, who led the most laps at Fontana.
Power and Penske jointly held up an Australian flag on the victory podium before Power raised the Astor Cup.
''There's no question that Will deserves this championship,'' Penske said. ''He won a number of races, a lot of poles, and really brought some momentum to this team. He deserved it. He was the best road racer, and to see him operate on the oval this year showed me he's got it.''
Castroneves was essentially finished after a drive-through penalty for a pit entry violation with 31 laps to go, sliding out of the groove onto the track on his way into the pits. The penalty paved a championship finish for Power, who has been dinged numerous times this season by pit road penalties.
For the sixth time in his career, Castroneves missed the title despite entering the final two IndyCar races in the top two in the points standings.
''It stings a little bit, but that's what motivates me,'' Castroneves said. ''It's good to be upset when you finish second in a championship. It gives me another reason to come back stronger next year and fix what we can fix to win a championship.''
Power beat Castroneves by 62 points for the title. Scott Dixon, the 2013 series champion, ended up third in the standings after a strong finish to the season.
Rookie Mikhail Aleshin's frightening crash late in a practice session reduced the field, but it didn't change Power's strategy. He was concerned by multiple crashes in the Fontana race in previous seasons, including his own spectacular flop in 2012.
Instead, the race was nearly uninterrupted - and Power did everything correctly.
''That's 15 years of hard work,'' Power said. ''It's just surreal, man. I can't believe it.''