NASCAR's Sprint Cup Series is under the lights this weekend for Saturday's IRWIN Tools Night Race at Bristol Motor Speedway. Last season, Brad Keselowski took the lead from Martin Truex Jr. just after a restart with 80 laps remaining and took the checkered flag by 0.95-seconds. The last seven Bristol races have had a margin of victory under one second. Keselowski has posted seven straight top-10 finishes this season, including a win in Kentucky. Keselowski also won earlier this season at Bristol. Greg Biffle won last weekend at Michigan to take a 20-point lead over Matt Kenseth atop the Cup Standings. Dale Earnhardt Jr., Jimmie Johnson and Keselowski round out the top-five.