The stunning victory is worth $11.53 million to former world No. 1 McIlroy, who conjured up a series of magical shots in a thrilling finale to the PGA Tour season.
It was clinched with a birdie putt on the 16th, the fourth hole of the playoff to finally see off the challenge of Moore, with Chappell having dropped out at the first extra hole.
Both Moore and McIlroy parred the next two playoff holes before the Northern Irishman sealed his double triumph.
A win for Moore would have given US Open champion Dustin Johnson the FedEx Cup series and the $10 million bonus on offer at Atlanta’s East Lake course.
Johnson, in the joint lead overnight, slipped to a final-round 73 to leave his fate in the…