Australian Will Power's drive towards the 2016 IndyCar Championship has suffered a damaging blow.
Power crashed in the 39th lap of the IndyCar Grand Prix at Watkins Glen International and was not allowed to return to the race because of concussion symptons.
He was credited with a 20th placed finish as New Zealander Scott Dixon won the race after leading for all but 10 of the 60 laps.
Power's No.12 Team Penske Chevy made contact with Charlie Kimball coming out of the high-speed esses.
Kimball hit Power's left rear tyre in the narrow section of the track at the top of the hill.
He got a huge run on the outside and made contact, sending Power hard into the barrier and bringing out a caution as debris scattered all over the track.
Power is locked in a battle with Penske teammate Simon Pagenaud for the series championship.
He trails Pagenaud by 43 points going into the double points finale, the Grand Prix of Sonoma on September 18.
Pagenaud finished seventh. He was running fifth with 10 laps left, but had to back off to save fuel in the closing laps.
Watkins Glen International is a special place for Dixon.
It's his 40th victory overall, moving the New Zealander into fourth place on the career list.
He also won for the second time this season, and fourth time at The Glen.
When the series returned to the historic road course in upstate New York's wine country in 2005, Dixon won the first three races, his victory that first year snapping a 40-race winless streak.
