Castroneves is now tied for 13th in career American open-wheel wins with 25.
Helio Castroneves led 153 out of 200 laps from the pole to take the victory in the Indy Japan 300 at Twin Ring Motegi on Sunday.
It was Castroneves' third IZOD IndyCar Series win of the 2010 season, coming in the series' penultimate race. It was also Castroneves' second consecutive win, after taking the honors at Kentucky. The Brazilian Team Penske driver also won at Barber Motorsports Park earlier this year.
Castroneves won his 23rd major American open-wheel race in dominant fashion, handily beating his Chip Ganassi Racing rival Dario Franchitti and Penske teammate Will Power. Ryan Briscoe and 2008 winner Danica Patrick rounded out the top five, with defending race winner Scott Dixon directly behind in sixth.
Franchitti, who clinched the A.J. Foyt Oval Championship in this race by 16 points, positioned himself to make a run for his second consecutive IndyCar title at Homestead in two weeks. Franchitti now trails Power by a mere 12 points in the overall standings with only the Homestead-Miami Speedway race to go.
The race was hindered in the final stages by a 19-lap caution to clean up debris spread by a major crash in turn two. Alex Lloyd dragged parts down the backstretch before finally coming to rest a long way from where he initially hit the wall. It was Lloyd's second caution of the day, after an early race caution had already cost him 16 laps in repairs.
Lloyd was not the only driver to make friends with the wall in Japan on the weekend of Friendship Day. Bertrand Baguette received terminal damage on the second lap of the race, while Mario Moraes only completed a third of the distance before hitting the wall. Moraes was removed from his car and put on a stretcher as he complained of back pain.
Three Japanese drivers took part in the race: Takuma Sato, Hideki Mutoh, and American-born Roger Yasukawa. All three completed the race; Sato finished 12th, Mutoh came home 14th, and Yasukawa placed 20th, five laps down. It was Sato's first IndyCar race in front of his home fans, Mutoh's first race in front of his father, and Yasukawa's first race of the season after previously spotting for Sato during oval races.
Only three drivers managed to lead laps during the event: Castroneves, Briscoe, and Raphael Matos, who inherited the lead by not pitting during the Moraes caution. However, an alternate pit strategy early did Matos no good later on, as he fell to 18th, the last car on the lead lap. Most drivers ended up finishing close to their starting positions, with Patrick (12th to 5th), Graham Rahal (16th to 8th), and Alex Tagliani (23rd to 13th) the three biggest gainers on the day.
The IZOD IndyCar Series will close out its 17-race schedule with the October 2 season finale at Homestead, the Cafes do Brazil 300. Franchitti took this race and the season championship with it last year.