MARTINSVILLE, Va. -- Trouble for the points leader and good runs for many of his closest pursuers left the Chase wide open on Sunday, setting up what is likely to be a wild four-race battle for the title.

Jimmie Johnson took the lead from Bobby Labonte with 55 laps to go and held it through several restarts to win the crash-filled Subway 500 at Martinsville Speedway, while 2003 champion Matt Kenseth replaced Jeff Burton atop the standings.

Johnson moved from seventh to third in the standings with four races left, and appears to be the driver with the most momentum heading into the final month.

"I'm just happy to finish where we should have," said Johnson, who was denied at least a second-place finish at Talladega when he was spun out on the last lap two weeks ago, then finished second last week at Charlotte.

"We've been running up front the last three of four races and haven't been able to close the deal. [Sunday] we did."

Kenseth assumed the points lead when Burton pulled his car into the garage after just 217 laps because of engine trouble, and most everyone took advantage.   More