During a successful four-race tryout in the Cup series in 2005 in the No. 11 FedEx Chevrolet, Denny Hamlin scored two top-10 finishes and two top-10 qualifying efforts and was promoted from within the Gibbs organization to pilot the car full-time.
In 2006, Hamlin had one of the most successful rookie seasons to date in the series. He swept the Cup events at Pocono that season and also posted 20 top-10 finishes. He started the sesason with a win in the Budweiser Shootout and became the first rookie to make the Chase. He finished third in the standings en route to winning the year's rookie of the year honors.
For 2007, Hamlin finished 12th in his third Cup season racing for Joe Gibbs. He won one race, finished in the top-five 12 times, and had 18 top-10s to conclude the season.
That year in the Nationwide Series, Hamlin posted three victories, five poles, 11 top-fives, and 16 top-10s racing 22 of the 35 Nationwide Series races to complete the season in 13th place.
Hamlin won a race and made the Chase in 2008, but it was still a frustrating season for the Joe Gibbs Racing driver. Despite scoring a victory at his home track in Martinsville, Virginia and qualifying for the post-season, Hamlin ended the year ninth in the standings and was never a serious threat to win the championship.
Hamlin experienced some tough blows during the season including an engine failure in August at Michigan that set off a controversy with the JGR team after some pointed remarks by the driver of the Fed EX Toyota.
He was also involved in a hard crash at Talladega in October at Talladega that resulted in an overnight hospital stay.
Hamlin did, however, manage to win four Nationwide races in just 19 starts in 2008.
In 2009, Hamlin posted his best NASCAR Sprint Cup Series season since his rookie year in 2006.
Hamlin posted career season bests in wins (4), top fives (15) and laps led (1,380) en route to his fifth-place finish in the standings. His last win of the season came in the season finale at Homestead-Miami Speedway, a track he had yet to win at.
If not for a couple engine failures and a costly mistake at Auto Club Speedway in the Chase, Hamlin could have found himself in serious contention to give Jimmie Johnson a run at the championship. With the exception of three DNFs, Hamlin recorded an average finish of 5.1 in the remaining seven races.