Harvick won the season-ending Ford EcoBoost 400 at Homestead-Miami Speedway on Sunday, reclaiming the lead late in the 267-lap race to earn his maiden title.
The Stewart-Haas Racing driver qualified quickest for the all-important race, and held the lead for 50 laps - but importantly overtook fellow contender Hamlin before retaining the lead despite a yellow flag with three laps to go.
Richard Childress Racing's Ryan Newman was Harvick's biggest threat for the race win, and also the title in the dying laps, but he could not get past the leader - finishing 0.500 seconds behind Harvick.
Newman never led, but still almost pinched the title despite starting from 21st on the grid.
Harvick was in sixth position with nine laps remaining, but got past both of Joe Gibbs Racing's Hamlin and Newman in quick succession.
Joey Logano was the other driver alive for the championship, but his challenge virtually ended when his crew let the number 22 car slip off the jack - costing the Team Penske man crucial seconds on his pit stop with just under 20 laps to go.
Hamlin ended up in seventh, while Logano was further back in 16th.
Rounding out the podium was Team Penske's Brad Keselowski, while pole-sitter Hendrick Motorsports' Jeff Gordon slumped to a 10th-place finish after having the race lead for 161 laps.