The 33-year-old North Irishman carded seven birdies to finish on 17-under-par at the Congaree Golf Club in South Carolina, a shot ahead of American Kurt Kitayama despite bogeying the final two holes.

As a result of his 23rd PGA Tour victory, the four-time major winner went to the top of the rankings for the ninth time in his career, overtaking Scottie Scheffler.

Asked what returning to No.1 meant to him, McIlroy told Sky Sports: "It means a lot. I've worked so hard over the last 12 months to get myself back to this place. I feel like I'm enjoying the game as much as I ever have.

"I absolutely love the game of golf. When I go out there and I play with that joy, it's definitely shown over these last 12 months."

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South Korea's K.H. Lee carded a 68 to finish third on 15-under, one shot clear of Jon Rahm (69) and Tommy Fleetwood (65).

Jason Day followed his three straight 69s with a 67 to tie for 11th, seven shots behind McIlroy while fellow Australian Cam Davis was a shot further back after a 70.