Jimmie Johnson wins the 2013 AAA 400 at Dover International Speedway

Jimmie Johnson's run toward a possible sixth NASCAR Sprint Cup Series championship shifted into high gear Sunday at Dover International Speedway. On two fresh tires to polesitter Dale Earnhardt Jr.'s four, Johnson held off his Hendrick Motorsports teammate during a 26-lap green-flag run to the finish of the AAA 400 and made a significant dent in the series lead of Matt Kenseth, who finished seventh. Johnson picked up his fifth victory of the season, his record eighth at the Monster Mile -- break...