Jimmie Johnson took over the lead in the Chase for the Sprint Cup championship by winning Sunday at Martinsville Speedway.  The five-time Cup champion now holds a two-point lead over Brad Keselowski with three races to go.  It was Johnson's 59th career victory and seventh at Martinsville.  Kyle Busch finished second followed by Kasey Kahne, Aric Almirola and Clint Bowyer.  Keselowski was sixth.  The series heads to Texas next week before closing the season with stops in Phoenix and Homestead-Miami Speedway.