Denny Hamlin went back-to-back at Dover Motor Speedway, holding a late lead through a rain delay and an overtime finish Sunday for the Joe Gibbs Racing driver's series-best fourth victory of the season.

With a 20th-place finish, Dillon -- the No. 32 and final seed in the In-Season Challenge -- advanced to the final round of the tournament, where he will race Gibbs (who won his matchup against Tyler Reddick) for a $1 million prize in next weekend's Brickyard 400 at Indianapolis.