Will Power won the season finale — a year after he crashed in this race to blow his own title chances — to salvage the night for Penske Racing.
But it was Dixon and Chip Ganassi celebrating on the big stage as the New Zealander won his third series title, and Target Chip Ganassi claimed its 10th championship since 1990. Dixon wrapped it up with a fifth-place finish. He was the final car on the lead lap, and beat Helio Castroneves by 27 points for the title.
"When you've won a couple, they are all very different," Dixon said about his three titles. "This year has been far different in that midyear we didn't think we had a shot at the championship."
It wasn't incident-free. Dixon, also the series champion in 2003 and 2008, nearly overheated late in the race.
"We were freaking out," admitted team manager Mike Hull.
Penske has now been denied in the season finale six times since Sam Hornish won the organization its last IndyCar championship in 2006. Ganassi has won five championships in that span.
"I feel for Helio," Dixon said. "He ran a strong year. He's a hell of a competitor."
This one slipped away in spectacular fashion as Castroneves led the points after 14 races this season and took a 49-point lead over Dixon into the Houston doubleheader two weeks ago. But a gearbox issue in the first race, which Dixon won, saw his lead sliced to just eight points.
Then in the second race, Castroneves drove over a bump in the track to cause a catastrophic failure to his gearbox. Dixon finished second and left Houston with a 25-point lead.
"One weekend for us, unfortunately for us cost us a lot of points," Castroneves said. "We did everything we could to avoid any kind of mechanical failure and the only time all season we had any kind of mechanical failure, that's what cost us the season. This is the tough part of racing."
It backed Castroneves into a position of almost certainly needing to win Saturday night's finale to salvage the title. But with the big boss on his pit stand calling the race — Penske told The Associated Press before Houston he'd call the final three races of the season and "if there's any mistakes, any issues, you can blame it on me" — Penske made a mistake.
He called Castroneves to pit lane before the pits were open during a late caution, and Castroneves was penalized by IndyCar. He went from fourth to eighth after the drive-thru penalty.
"I'm so sorry," Penske radioed.
Castroneves downplayed the mistake.
"That was just a blip on the radar," he said.
Instead, contact later with Dixon teammate Charlie Kimball broke Castroneves' front wing. The stop to replace it dropped him a lap down, and Castroneves was the first car a lap down with his sixth-place finish.
"I feel for Helio," said Dixon. "He ran a strong year. He's a hell of a competitor."
For Power, who was racing as much to help Castroneves win the title as he was for himself, ended the night with what he called "the most satisfying win of my life." Power had gone into the finale three years in a row with the championship on the line, but hit a seam in the speedway last year and crashed.
He's struggled most of this year and didn't pick up his first win of the year until Sonoma in August. He then added another victory two weeks ago at Houston, and Saturday night's win was his second career victory on an oval.
"I wanted to do it so badly all year," Power said. "I knew in the early ovals, I just was kind of conservative because I just wanted to finish every lap. And this time I'm going for it."
Only nine cars were running at the end, and a six-car accident just past the halfway mark sent Justin Wilson to a local hospital for evaluation. IndyCar medical director Dr. Michael Olinger said Wilson suffered non-operable fractures to his pelvis and a small pulmonary contusion.
The accident began when Wilson's car wiggled as his rear tire was caught in a seam on the track. The Brit tried to save it as his car began to spin toward the wall, but as he lost control, Tristan Vautier drove directly into the side of Wilson's car.
"I didn't see him before I hit him. There was a big cloud of smoke. Didn't see what was happening," Vautier said.
It took the safety team several minutes to get Wilson out of his car. He was placed on a stretcher and taken by ambulance to a local hospital.
The accident also collected Josef Newgarden, who in trying to avoid Wilson drove into Oriol Servia. James Jakes was also knocked out of the race, and in-car cameras showed a huge piece of debris sailing over his head.
"We were on the outside and in the smoke you lose perception of everything," Jakes said. "We lost our vision and then I got hit with the debris. Tough after starting fifth."
Simona de Silvestro's car suffered damage, but she was able to continue.
Before that, Carlos Munoz was impressive driving as the emergency replacement for E.J. Viso, who didn't make the trip to Fontana. Andretti Autosport said Viso was ill, although reports out of Venezuela indicated Viso could be affected by an investigation into the funding of motorsports drivers in that country.
So Munoz was given Viso's car to drive Saturday night, hours after winning the Indy Lights race for the second consecutive year. Munoz, who finished second in the Indianapolis 500 earlier this year, drove as high as second and was mixing it up with the leaders. But he was aggressive — too aggressive for Castroneves' team owner's liking — and Penske urged Castroneves to get away from Munoz.
It proved to be the correct advice when Munoz spun on Lap 101, ending his night.
"You were smart there. He was in totally over his head," Penske radioed Castroneves.