Hamlin won his first Busch race of the season and did so from the pole, finishing 1.432 seconds ahead of Mark Martin at Darlington Raceway.
NASCAR officials stopped the race with eight laps remaining so debris from a crash involving Bobby Labonte could be removed from the track.
Hamlin was out in front when the race was restarted and he got the jump on Martin. The battle over the closing laps was for second with Martin finishing in front of Carl Edwards.
Edwards' third-place finish allowed him to increase his points lead to 433 over Kevin Harvick.