In 2008 Keselowski re-signed with JR Motorsports for the 2008 Nationwide Series season, and earned his first career victory in the Federated Auto Parts 300 at Nashville Superspeedway, holding off Clint Bowyer. Keselowski would hold off Bowyer again for his second career win in the Food City 250 at Bristol Motor Speedway. He ended the season third in points, the highest finish by a full-time Nationwide Series-only driver. Keselowski also got his first taste of Sprint Cup action during the 2008 season. He was on standby for an ill Jeff Gordon at Kansas and for expectant father Casey Mears at Talladega, before competing in two races for Hendrick Motorsports in the No. 25 GoDaddy.com Chevrolet Impala. Keselowski finished 19th in his Cup debut, the Dickies 500 at Texas, and 23rd in the Ford 400 at Homestead.