Motegi, Japan (My Sportsbook) - Scott Dixon's bid for a second straight IndyCar Series championship got a huge boost Saturday after the Chip Ganassi Racing driver won the Indy Japan 300 in dominating fashion at Twin Ring Motegi.

Dixon, the pole sitter, capitalized on Ryan Briscoe's unfortunate pit road accident midway through the race. He finished 1.4 seconds ahead of teammate Dario Franchitti for his series-leading fifth victory of the season.

"It's definitely what we needed," Dixon said. "We needed to have a few problems on the Penske side, and that was definitely true today."

Dixon earned two bonus points for leading the most laps with 139. He holds a five-point lead over Franchitti and an eight-point advantage over Briscoe heading into the October 10 season-ending race at Homestead-Miami Speedway.

The closest three-way battle for the title entering the season-finale occurred in 2003, with seven points separating the top-three drivers. Dixon won his first championship that year, defeating Gil de Ferran by 18 points.

"As long as we come out on top -- either Dario or myself -- for the championship, that's what we are pushing for," Dixon added. "If we can pull that out at Homestead, that's definitely what we want."

Briscoe came to Motegi with a 25-point lead, but the Team Penske driver lost control of his car and slammed into the inside wall after he exited his pit stall on his second scheduled stop. He suffered suspension and front wing damage from a yellow cone that lodged underneath his car during the wreck. Briscoe spent 15 laps in the pits for repairs before ending up with a disappointing 18th-place finish.

"I just gave it a bit too much throttle as I transitioned onto the tarmac, and it just spun me around," Briscoe said. "It caught me by surprise, and there were no excuses."

Briscoe had an opportunity to gain valuable track position when he made his pit stop just before the first caution flag waved for an accident involving rookie Mike Conway.

Franchitti and Dixon both pitted for the final time with 40 laps to go, but Dixon won the drag race out of the pits and grabbed the lead for good after the cycle of green-flag stops was completed. Franchitti's second-place finish gave Ganassi a one-two finish.

"To finish one-two was good, but I would have preferred it was us," Franchitti said.

Graham Rahal came in third, followed by Oriol Servia and Mario Moraes.

Danica Patrick, who won here in April 2008 for her first career IndyCar victory, finished sixth.

Marco Andretti, Dan Wheldon, Raphael Matos and Helio Castroneves completed the top-10. Castroneves had to start from the rear of the field after crashing during his qualifying attempt on Friday. The Penske driver finished one lap behind.