The Associated Press

LONG POND, Pa. - Late caution flags helped Ryan Newman stretch his gas to the end, allowing him to barely hold off hard-charging Kurt Busch and win Sunday at the Pennsylvania 500.

Newman, who started on the pole, would not have been able to make the final 46 laps without stopping. But crashes involving rookie Casey Mears and Bobby Labonte slowed the field for a total of 12 laps at Pocono Raceway.

Newman used the same strategy to win two weeks ago at Chicagoland Speedway, and Jimmie Johnson won with a fuel economy run last Sunday in New Hampshire's New England 300.

Newman said he wasn't thinking entirely about fuel as Busch made a determined bid after the race went green for the final 12 laps.

"The 97 there at the end, I had to do some stuff to keep his nose in the dirty air," Newman said. "Fuel mileage and track position paid off."

Busch never let up in a battle between the biggest winners this season on the Winston Cup circuit.

"It was a great day," he said. "But he was in position to win."

Busch nearly provided the first victory on the mountaintop for Roush Racing - now a five-car unit - since the team entered Winston Cup racing in 1988. But every time he pulled within a car-length or two, Newman got away.

IRL: Alex Barron passed Sam Hornish Jr. coming out of the final turn to win the Firestone 400 Sunday with the fastest average speed in Indy Racing League history, 180.916 mph.

Barron won by just 0.0121 seconds, the fourth-closest race in the league's eight years. His second career victory came only because he avoided what could have been the end of his race on the 164th lap at Michigan International Speedway.

Side-by-side contact with Tomas Scheckter made Barron's car wiggle, slide to the infield and turn 180 degrees before he was able to straighten out the car.

The crowd of more than 30,000 gave him a standing ovation.

"I wasn't really scared," Barron said. "I was more worried about damaging the car, because we were having such a great day."

Scheckter, whose only win was in Michigan last season and who started on the pole Sunday, finished third, followed by Scott Sharp. Scott Dixon's fifth-place finish was good enough to give him the season points lead - by one - over Tony Kanaan, who dropped out on the 151st lap with engine failure.

CART: Paul Tracy bounced back from another dispute in his rocky relationship with CART officials by turning the Vancouver Molson Indy into a rout.

The victory - his fifth of the season - stretched his lead from 15 points to 20 over Bruno Junqueira in Tracy's quest for his first CART championship.

It also marked the end to a tumultuous weekend for Tracy, sometimes considered CART's "bad boy" but also its hottest, rising star.

He said he felt "betrayed" by CART over a series of recent calls against him, including Friday when the sanctioning body stripped him of the provisional pole and the championship point that goes with it after Tracy blocked other cars during qualifying.