A jubilant Dale Earnhardt Jr. broke through for his first NASCAR Nextel Cup victory of the season, using a two-tire strategy and holding off Matt Kenseth to win at Chicagoland Speedway in Joliet, Ill.

"I was worried I was going to go winless this year," the relieved Earnhardt said after smoking the tires on his No. 8 Chevrolet and celebrating with his crew in the infield grass. "Now, let's go out and do it again, win some more."

Kenseth led 176 of the 267 laps but wound up second after choosing to change four tires and falling behind on his final pit stop in the USG Sheetrock 400.

Earnhardt has had a mostly miserable season and had little reason to smile until he turned in a third-place finish last week at Daytona. He started 25th yesterday and spent most of the day hovering near the end of the top 10.

The last of 10 caution flags waved on Lap 249, when Mike Bliss and Jeff Gordon crashed, giving all the leaders a last chance to pit on a day when right-side tires were blistering and causing numerous blowouts and crashes.

Scott Wimmer stayed on the track and took the lead, while Earnhardt and several other drivers took only two tires and moved ahead of both Kenseth and Tony Stewart.

It took Earnhardt three laps to get past Wimmer after the green flag came out on Lap 255. Meanwhile, Kenseth charged toward the front, grabbing second place from Brian Vickers on Lap 261.

But Kenseth couldn't catch Earnhardt, finishing about five car-lengths back.

Jimmie Johnson, the series points leader, came back from a lap down to finish third, followed by Vickers and Stewart.

* FORMULA ONE: In Silverstone, England, Juan Pablo Montoya took a risk to win the British Grand Prix, one of the few moves that's worked this season for the former Indy 500 champion.

He beat Fernando Alonso, who finished second to extend his points lead. This was Montoya's first victory of the season and first with McLaren-Mercedes.

Montoya started third behind pole-sitter Alonso. He nearly brushed Alonso going through the first turn and, at the next corner, he swept by as the Spaniard slowed to avoid a crash.

"One of us was going to back off, or we were going to go off," Montoya said after his fifth career victory. "And the chances are he was going to back off before me. He has got a fight for the championship, and I just wanted to win the race."

* CHAMP CAR: Justin Wilson passed Oriol Servia with 11 laps to go at the Toronto Molson Indy and held on for his first series victory.

A.J. Allmendinger, Wilson's teammate for the upstart RuSport team, crashed as he was closing in on Servia for second place. Allmendinger brushed the wall then careened across the track into a tire barrier.

Mario Dominguez then slammed into Allmendinger's stopped car to bring out a caution with seven laps to go. The race ended when officials were unable to get the track cleaned during the allotted time the series had to finish the event.

* MOTOGP: Nicky Hayden became the first U.S. rider to win a world MotoGP race in five years, leading from start to finish to beat fellow American Colin Edwards in the U.S. Grand Prix.

Hayden earned his first win in 38 MotoGP starts before a crowd of 57,000 at Laguna Seca Raceway in Monterey, Calif.

"This feels so good," Hayden said. "I got a good start, I kept my head down and never let up."

Edwards finished second, 1.941 seconds back to give the United States its first 1-2 finish on the MotoGP circuit since the 1993 Spanish Grand Prix.

Dale Earnhardt Jr. burns rubber in celebration of his first Nextel Cup win of the season. "I was worried I was going to go winless this year," he said.