Greg Biffle celebrates his victory in the NASCAR Sprint Cup Pure Michigan 400 at Michigan International Speedway Sunday. Biffle slipped into the lead on a green-white-checker finish to take the victory.

Greg Biffle (right) celebrates his victory by spraying teammates at Michigan.

Greg Biffle hoists his trophy following his second NASCAR Sprint Cup win of the season.

Jimmie Johnson started at the back of the pack and before long moved himself into contention at Michigan on Sunday. But after taking the lead with less than 10 laps to go, his engine blew with six laps left. He ultimately lost the race and his points lead — Greg Biffle taking both.

Bobby Labonte spins after contact with Juan Pablo Montoya right in front of leader Mark Martin.

Regan Smith wrecks during the NASCAR Sprint Cup race Sunday.

Bobby Labonte slides around Turn 4 during the NASCAR Sprint Cup Pure Michigan 400 auto race at Michigan International Speedway, Sunday, Aug. 19, 2012, in Brooklyn, Mich. (AP Photo/Dave Frechette)

Greg Biffle (16), Kevin Harvick (29) and Regan Smith (78) battle for position during the NASCAR Sprint Cup Pure Michigan 400 at Michigan International Speedway Sunday. Biffle would go on to win the race.

Jimmie Johnson (48) passes Joey Logano (20) early in the race at Michigan. Johnson would go on to suffer a major setback in the closing laps.

Mark Martin (55) leads the field to the green flag to start the NASCAR Sprint Cup Pure Michigan 400 Sunday afternoon.

Mark Martin signs an autograph before leading the field to the green Sunday.

Jeff Gordon (right) laughs with crew members before the race.

Dale Earnhardt Jr. looks over his car before the race.

Nelson Piquet Jr. celebrates in Victory Lane after winning the NASCAR Camping World Truck Series VFW 200 at Michigan International Speedway on Saturday.

Tim George Jr. (No. 2) leads Matt Crafton (88) and Brennan Newberry (14) through a turn during the NASCAR Camping World Truck Series VFW 200 at Michigan International Speedway on Saturday.
 

Joey Coulter leads the field to the green flag to start the Truck Series race in Michigan on Saturday.

Nelson Piquet Jr., who went on to win the race, leads a pack of trucks during the NASCAR Camping World Truck Series VFW 200 at Michigan International Speedway.

Todd Bodine (11) spins after being involved in a mishap as other drivers try to maneuver around during Saturday's Truck Series race in Michigan.

The crew of Jacques Villeneuve works on a tire change during the NASCAR Nationwide Series NAPA Auto Parts 200 presented by Dodge on Saturday at the Circuit Gilles Villeneuve in Montreal. Villeneuve finished third.
 

The field chases after leader Danica Patrick during the NASCAR Nationwide Series race in Montreal on Saturday. Patrick was derailed by driving over a shoe that had fallen on the track.

Justin Allgaier makes a splash by winning the Nationwide Series event in Montreal on Saturday.

Jacques Villeneuve heads the field during the NASCAR Nationwide Series NAPA Auto Parts 200 presented by Dodge in Montreal.

In case you don't get the message, Mark Martin wins the pole for Sunday's Sprint Cup race, the Pure Michigan 400 at Michigan International Speedway.

Juan Pablo Montoya runs to the No. 25 qualifying spot for Sunday's Sprint Cup race at Michigan International Speedway.

Jeff Gordon wore a smile during qualifying for the Pure Michigan 400. He got the No. 11 spot.

Danica Patrick gets into her NASCAR Nationwide Series car prior to practice for the NASCAR Nationwide Series race at the Circuit Gilles Villeneuve in Montreal.

Patrick Carpentier takes on the Circuit Gilles Villeneuve road course in Montreal.

Ron Fellows drives during practice for the NASCAR Nationwide Series race in Montreal.

Kasey Kahne looks focused as he prepares for NASCAR Sprint Cup practice at Michigan International Speedway Friday. Kahne is currently the leader among drivers battling for a wild-card spot in the Chase for the Sprint Cup.

Jimmie Johnson talks during practice at Michigan International Speedway. Johnson enters the race as the NASCAR Sprint Cup points leader.

Martin Truex Jr., fifth in the standings, prepares for practice at Michigan.

Trevor Bayne sits waiting to take the Wood Brothers Racing Ford out onto the track at Michigan. Bayne and the team are competing in a limited number of Cup races this season.

Penske Racing's Sam Hornish Jr. takes laps in Montreal Friday.

Kurt Busch drives the No. 18 Shore Lodge Toyota during practice for the NASCAR Camping World Truck Series VFW 200 at Michigan International Speedway Friday.