Scot Dario Franchitti has walked away uninjured from his second huge airborne accident in six days - the latest one after the race had finished.
Franchitti's points lead has been cut right down
The Indianapolis 500 winner careered into the car of rival Kosuke Matsuura after taking the chequered flag at the Indy Racing League event at Kentucky.
Franchitti's car flipped, pirouetted on its nose and landed against the wall.
"That one was completely my fault; there's no excuse," said Franchitti. "I didn't realise it was the chequered."
The 34-year-old, who was eighth, saw his series lead cut to eight points by New Zealander Scott Dixon, who finished a close second to Brazilian Tony Kanaan, who is third in the points race.
Franchitti had been disputing second place with Dixon when he got off line on the 1.5-mile tri-oval and slipped back to sixth.
He lost two more places when he clipped a flag entering the pit lane and damaged the nose of his car.