Justin Thomas claimed his second CJ Cup trophy after reigning supreme in South Korea on Sunday.

American star Thomas carded a five-under-par 67 in the final round to triumph by two strokes on Jeju Island.

Playing outside of the United States, where Thomas won the PGA Tour tournament in 2017, the former world number one withstood a duel with runner-up Danny Lee.

Thomas entered the final day tied for the lead alongside South Korean-born New Zealander Lee (69) at Nine Bridges Golf Club.

The pair continued to go toe-to-toe during the final 18 holes, sharing the lead down the stretch, but back-to-back bogeys at the 15th and 16th dashed Lee's hopes.

Thomas birdied three holes on the back nine, capping his triumphant performance with another birdie at the last to finish 20 under for his 11th Tour crown.

Hideki Matsuyama (65), Gary Woodland (66) and Cameron Smith (69) finished in a share of third position, five shots adrift of Thomas.

Three-time major champion Jordan Spieth was unable to maintain his charge following a final-round 71.

Spieth had four bogeys to go with five birdies as he fell four positions into a tie for eighth – eight shots off the pace.

Meanwhile, American veteran Phil Mickelson (68) ended the event tied for 31st, a shot ahead of former world number one Jason Day (71).

Danny Lee moved into a joint lead with Justin Thomas after round three of the CJ Cup in South Korea.

South Korean-born New Zealander Lee was in a tie for second place with first round leader An Byeong-hun at Nine Bridges overnight and enjoyed a remarkable final hole swing on day three to draw level with Thomas.

The American was moving towards an 11th PGA Tour win midway through the round when Lee double-bogeyed hole 10 and local hope An triple-bogeyed at the 11th.

But Thomas bogeyed the last and Lee capitalised with superb eagle on the par-five 18th to complete a three-shot turnaround and cap a round of 68, ending the day with momentum.

The pair sit at 15 under par with one round remaining, three shots clear of Australian Cameron Smith, with Jordan Spieth and Wyndham Clark tied for fourth and a shot further from the pace.

Elsewhere, Ian Poulter made two eagles on the back nine to spring into contention at nine under while Viktor Hovland's tour record streak of 19 consecutive sub-70 scores ended with a two-over 74.

Defending champion Brooks Koepka pulled out of the event with a knee injury on Friday.

Brooks Koepka has withdrawn from the CJ Cup due to a knee injury.

Reigning champion Koepka, who last won at the WGC-FedEx St Jude Invitational in July, was even par through his first two rounds at Nine Bridges, located on Jeju Island in South Korea.

Prior to the 2019-20 season the four-time major winner had stem cell-treatment to repair a partially torn patella tendon in his left knee.

He missed the cut at the Shriners Hospital for Children Open two weeks ago – his first tournament since returning.

It is unclear how serious Koepka's injury is or when he will be back on the course.

Justin Thomas went into round three of the CJ Cup at the top of the leaderboard and with a two-shot lead.

Justin Thomas earned a two-stroke lead with a sizzling performance at the halfway stage of the CJ Cup in South Korea on Friday.

American star Thomas used a bogey-free nine-under-par 63 to surge to the top of the leaderboard following the second round.

Thomas started his day with four successive birdies and finished with nine in total, including one at the last as he catapulted himself eight positions into the lead at 13 under through 36 holes.

Winner of the PGA Tour tournament – which is being played outside of the United States this year – in 2017, Thomas leads An Byeong-hun and Danny Lee heading into the third round.

Local hope An (69) and New Zealand's Lee (66) are tied for second at the Nine Bridges Golf Club on Jeju Island.

An carried a one-shot lead into the second round but the South Korean lost his spot at the front of the queue following two bogeys and five birdies, while Lee improved to 11 under but he could have ended the day a stroke better off if not for a bogey at the 18th.

Emiliano Grillo (66) and former world number one Jordan Spieth (65) are four shots off the pace ahead of Saturday's penultimate round.

Spieth was a big mover at the CJ Cup, with the three-time major champion climbing 25 positions into a tie for fourth, thanks in part to back-to-back birdies to end the day.

The American almost aced the 17th after his tee shot fell just short of the hole, highlighting a fine display from Spieth.

Jason Day struggled as the Australian's second-round 73 saw him drop down to five under, while defending champion Brooks Koepka also had a round to forget.

Looking to defend his title, Koepka was unable to back up his opening-round 69 after shooting a three-over-par 75 – a round that included five bogeys and left him even par.

Local hope An Byeong-hun holds a one-shot lead after round one of the CJ Cup.

The South Korean shot an eight-under 64 on the opening day at Nine Bridges to hold a slender lead over Chilean Joaquin Niemann, with Australian Jason Day one stroke further back. 

Americans Charley Hoffman and Charles Howell III are among the chasing pack at five-under, having spent most of the day challenging at the top of the leaderboard.

Defending champion and world number one Brooks Koepka had something of a frustrating round but nailed an eagle on the 18th to finish at three-under.

The opening day belonged to An, though, as he finished with eight birdies – including four on the back nine – to move into the lead.

Only Niemann bettered An's run at the back end of Nine Bridges with five birdies, including two on holes 17 and 18.

Brooks Koepka insists he does not have a rivalry with Rory McIlroy because the Northern Irishman has not won a major since 2014.

World number one Koepka has enjoyed a phenomenal run in golf's major events over recent years, claiming victory at the 2017 and 2018 U.S. Opens and 2018 and 2019 US PGA Championships.

In 2019, as well as winning the US PGA, he finished tied second at the Masters, second at the U.S. Open and tied fourth at The Open Championship.

McIlory, ranked number two in the world, finished last season by claiming the FedEx Cup and was named the PGA Tour's player of the year – voted for by his fellow professionals.

But the 30-year-old's wait for a fifth major now stands at five years, dating back to his triumph at the 2014 PGA Championship.

Speaking ahead of his CJ Cup defence, Koepka mischievously offered a reminder of this when the prospect of a rivalry with McIlroy was discussed.

"I've been out here for, what, five years. Rory hasn’t won a major since I’ve been on the PGA Tour. So I just don't view it as a rivalry," Koepka said, as per AFP.

"I'm not looking at anybody behind me. I'm number one in the world. I've got open road in front of me. I'm not looking in the rearview mirror, so I don't see it as a rivalry.

"You know if the fans do [call it a rivalry], then that's on them and it could be fun."

Koepka made sure to point out he remains a huge admirer of McIlroy's game and suggested his stance on rivalries might have more to do with golf as a sport in general.

"Look, I love Rory. He's a great player and he's fun to watch," he added. "But it's just hard to believe there's a rivalry in golf. I just don't see it."

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