Mark Martin, driver of the #5 Hendrickcars.com/GoDaddy.com Chevrolet, loses his tire on the track during the NASCAR Sprint Cup Series Kobalt Tools 500 at Atlanta Motor Speedway. (Photo: Getty Images)

Kevin Harvick, who finished ninth, kept the point lead. Kenseth is second, Greg Biffle third, Jimmie Johnson fourth and Clint Bowyer fifth.

For the first time this season, significant tire issues played a role in the race. There were numerous punctures or blowouts during the event, which finished one second short of four hours.

Caution No. 8 was produced when a left-front tire blew on Denny Hamlin’s car, forcing the field to slow at lap 288. A few laps later, on the restart, the cars of Elliott Sadler and Max Papis made contact, sending the caution flag into the air again.

Johnson pitted during that caution so that his team could repair damage Johnson’s car received when he and Ryan Newman bumped.

A right-front tire popped on Joey Logano’s car on lap 158, severely damaging the front of the Toyota and producing the day’s sixth caution.

Mark Martin slid along the frontstretch on lap 114 when his car lost its left-rear tire. Martin kept the car off the wall, but his Chevrolet later was damaged severely in the caution that resulted from the first green-white-checkered attempt. He failed to finish and was 33rd on the result sheet.

The first Keselowski-Edwards incident caused the first multi-car caution flag of the day on lap 40.

A blown tire sent David Ragan into the third-turn wall on lap 35, causing the second caution of the race. The event had barely started when a tire problem sent Robby Gordon into the first-turn wall.

RESULTS: KOBALT TOOLS 500

Mike Hembree is NASCAR Editor for SPEEDtv.com and has been covering motorsports for 28 years. He has written several books on NASCAR, including "NASCAR: The Definitive History of America's Sport" and "Then Tony Said To Junior: The Best NASCAR Stories Ever Told". He is a six-time winner of the National Motorsports Press Association Writer of the Year Award.