New Zealand driver Scott Dixon has claimed his fourth Indy Car series championship in California after winning the final race of the year, the Sonoma Grand Prix.
Dixon was third in the overall standings before Monday's final race and had to win the race and hope series leader Juan Pablo Montoya finished no higher than sixth.
Dixon duly did his part - producing a great race to win the event - and heading into the final lap sixth-placed Montoya was chasing hard to push his way into fifth.
But he could not catch fifth-placed Charlie Kimball, handing Dixon the narrowest of overall title victories.
The pair finished tied on 556 points, but Dixon was handed the IndyCar crown by virtue of winning more races this season, taking three races to Montoya's two wins.
The 35-year-old New Zealander has now claimed four titles after series wins in 2003, 2008 and 2013.
It is also the second year in a row that Dixon has won the final race of the year in the IndyCar series.
Dixon delivered the 100th victory for Chip Ganassi Racing Teams and the team's 11th championship.
"There was still a chance and that's what I was hoping for," Dixon said of the double-points race. "I don't know what to say. This season we had some big races, and this was the biggest. We were such a longshot."
Dixon's season started with 15th- and 11th-place finishes before he won at Long Beach in mid-April. He also recorded a win in the Firestone 600 at Texas Motor Speedway in early June and closed with six top-10 finishes in the succeeding seven races.
Dixon inherited the lead for good on Lap 63 on a pit stop exchange and withstood several challenges by Hunter-Reay in the closing laps on the technical racetrack.
"I knew the car was strong. We were getting fuel mileage so easy, which was key," he said. "We could roll the car through the corner and obviously get the mileage. You never know until the last lap. That's what it came down to. You hope for it. We had to do our best job and that's what we did today and luckily enough it worked out."