World number three Rory McIlroy scooped the Tour Championship and the FedEx Cup in Atlanta on Sunday.
The 27-year-old put himself in contention for the crown when he eagled the 16th hole and finished the round with a 12-under-par 64.
After Chappell was eliminated on the first playoff hole, McIlroy ousted Moore by rolling in a 15-foot birdie putt to win the Tour crown and the $10m (£7.7m) FedEx Cup prize money.
Dustin Johnson led the points race heading into the tournament in Atlanta, but he dropped down the field in the final round following three bogeys and a double bogey on the 12th hole.
The American ended the day with a 73 and seven shots off the top spot.