Rory McIlroy reclaimed the world number one ranking after his first win of the new season and the 23rd of his PGA Tour career, securing the CJ Cup with a score of 17 under par.

McIlroy took the outright lead on the 14th hole with his fifth birdie of the day and built a tournament-winning lead with two more birdies on the next two holes on his way to a Sunday 67.

Those extra insurance birdies ended up coming in handy after the Northern Irishman bogeyed the final two holes, but Kurt Kitayama could not birdie the last to force a playoff.

He entered the final round leading by one stroke, and by finishing the same way, he leapfrogged Scottie Scheffler to the top of the world rankings as the American finished tied for 45th at one under.

Speaking to NBC after stepping off the final green, McIlroy spoke about his love for the game and his journey back to the top.

"It feels great," he said. "It feels great to go out there with the lead, shoot a great score, play really well and get the win.

"It's an awesome way to start the season, I guess, and a continuation of how I feel I've been playing the past few months.

"[Becoming world number one] 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 play with that joy – it's definitely shown over the past few months. It feels awesome, I'm looking forward to celebrating with my team."

Kitayama finished alone in second at 16 under, with Lee Kyoung-hoon the only player in third at 15 under.

Tommy Fleetwood shot Sunday's equal second-best score with a 65 to jump up into a tie for fourth at 14 under with Jon Rahm.

Aaron Wise finished alone in sixth at 12 under and an all-American group headlined by Sam Burns rounded out the top-10, tied for seventh at 11 under.

The best fourth-round score came from Taylor Montgomery, who was three strokes better than the field on the last trip around Congaree Golf Cup with his nine-under 62 – finishing his tournament at nine under after entering the round at even par.