Hamlin passed Mark Martin with 28 laps remaining and later held off a stiff challenge from Matt Kenseth during a three-lap shootout to the finish. It was Hamlin's eighth Sprint Cup victory of the season.
The victory also enabled Hamlin to establish a 33-point championship Chase lead over Jimmie Johnson, who came in ninth Sunday -- first time in five years that Johnson hasn't led in points with two races to go.
Kenseth finished second, followed by Martin, Joey Logano and Greg Biffle.
Kevin Harvick. meanwhile, fell 59 points behind Hamlin with his sixth-place finish.
The race featured an on-track shoving match between Jeff Gordon and Jeff Burton after Burton bumped Gordon and the two drivers slammed hard into the wall.
The drivers emerged from their cars and engaged in a physical altercation before NASCAR officials intervened.