The World No.2, who claimed the Zurich Classic team event alongside Shane Lowry a fortnight ago, started Sunday's final round one behind Schauffele but romped home with an inward 32 to win in style.

A six-under 65 saw McIlroy finish 17-under as he triumphed at Quail Hollow for a fourth time and provided the perfect tune-up for this week's PGA Championship at Valhalla – the scene of his most recent major title in 2014.

"I really got some confidence," McIlroy said. "My golf swing feels a lot more comfortable than it has.

"So going to a venue next week where I've won, it feels like the stars are a lining a little bit.

"But I've got a lot of golf to play and a lot of great players to try to beat next week. Going into the next major of the year feeling really good about myself."

Schauffele finished five behind in second after stumbling to a 71, with South Korea's An Byeong-hun third on nine-under after a 66.

Australia's former World No.1 Jason Day continued his career resurgence, finishing tied fourth with Sungjae Im at six-under after a closing 70.

His countryman Adam Scott (71, two-over) was tied 21st while Cam Davis faltered with a 77 to be tied 38th at four-over.

McIlroy found himself two shots back after Schauffele eagled the 7th hole.

However, the Northern Irishman stormed back with birdies at the 8th and 9th before producing an eagle of his own from 34 feet at the 10th.

Schauffele was only one-under for the same three-hole stretch to leave the four-time major winner one ahead.

McIlroy found himself two in front as Schauffele dropped a shot on the 12th and ramped up the pressure on his playing partner with a birdie from 13 feet at the short next.

Schauffele failed to save par after hitting his tee shot into rough behind the green on the 13th to leave McIlroy four clear.

"He's Rory McIlroy, you know?" Schauffele said. "He hits it 350 yards in the air downwind and he has shorter clubs into firm greens than anyone else. When he's on, he's on. Hats off to him for winning. He played unbelievably well."

McIlroy got up and down from a greenside bunker for another gain at the driveable 14th, with Schauffele missing from five feet to leave his rival five clear.

An eagle from a greenside bunker on the 15th eliminated any prospect of a nervy finish for McIlroy and the 35-year-old parred the 16th and 17th before dropping two shots on the last after hitting his approach in the water.