The 28-year-old American, in his third season on the tour, began the final day tied for the lead with compatriots Joel Dahmen and Jason Dufner at 11 under.

He dropped only one shot in an assured round of 67 to finish at 15 under.

Justin Rose carded a 68 and was third on 11 under, while playing partner Rory McIlroy, two back overnight, was eight adrift in a tie for eighth after a 73.

Homa rolled in his third birdie of the day to open a two-shot lead at the 10th and that soon became three when the animated joint first-round leader Dahmen, 31, also seeking his first PGA title, dropped his second shot in three holes.

The lead grew to four when Homa, whose previous best finish was tied for sixth at the 2015 Sony Open, struck a superb iron to five feet for another birdie at the 11th.

Before he could attempt a five-foot par putt at the 14th, a torrential hail storm took the players off the course and left the Quail Hollow greens under water.

But after a 62-minute delay, Homa calmly holed the putt in the late afternoon Charlotte sunshine.

Rose made three birdies in four holes around the turn to set the target, but despite dropping a shot at the 16th after finding a fairway bunker, Homa made two confident closing pars to take the title and a place at the PGA Championship later this month.

McIlroy, twice a winner of the event, three-putted the seventh to only make par and another three-putt led to a dropped shot at the ninth.

At the 10th he was just short of the green in two but a combination of misjudged chips and a missed putt meant he took another five strokes and recorded a double bogey.

A superb eight-iron to two feet at the 181-yard 13th gave the four-time major champion the first of only two birdies in his final round.