The 2004 series champ wrested the race's lead from Jimmie Johnson after a late-race restart and went on to log his second win of the season and the 24th of his career.
With the victory, Busch tied at Tony Stewart -- who finished 25th Sunday -- at nine points out of the lead.
Stewart, who won the first two Chase for the Championship races at Chicagoland and New Hampshire, finished in 25th place Sunday.
Harvick, meanwhile, finished 10th.
Kasey Kahne and Matt Kenseth rounded out the Top 5 at Dover.