20-year-old Kim Joo-hyung became the second-youngest player since 1932 to win a PGA Tour event – trailing only Jordan Spieth – as he produced a final-round 61 to run away with a five-stroke buffer and claim the Wyndham Championship at 20 under.

In doing so, he became the event's youngest ever winner, and after entering the last tournament of the season ranked in the 400s in the FedEx Cup standings, he booked his place in the playoffs later this month.

His final round included an incredible front-nine score of 27, with six birdies and an eagle, and making his win even more remarkable is the fact that he started his week with a quadruple bogey from his opening hole on Thursday.

Speaking to CBS after stepping off the final green, Kim said his ability to keep a sense of humour about his rough start was the key to bouncing back.

"I stayed very patient this week," he said. "I felt like after that quad, once I started to laugh it off I could feel like I was in a much better mental state. 

"Instead of being angry and depressed I just stayed in the moment – I can't believe I won with a quadruple bogey on the first hole – hopefully that doesn't happen again.

"It's definitely a week I will remember forever."

He added: "it was a hard day – I didn't know golf was this stressful before."

Finishing in a tie for second was Kim's South Korean compatriot Im Sung-jae and American John Huh at 15 under, with Ben Griffin alone in fourth at 14 under.

American trio Max McGreevy, Russell Henley and Taylor Moore tied for fifth at 13 under, and there was another two-stroke gap to the group rounding out the top-10 at 11 under consisting of England's Tyrrell Hatton, Australia's Cameron Percy, India's Anirban Lahiri, and Americans Brandon Wu and Chesson Hadley.

Germany's Stephan Jaeger posted Sunday's second-best round with a 62 to finish tied for 13th at 10 under, and Canada's Corey Conners produced a pair of 66s on the weekend to sit on the fringe of the top-20 after scraping through right on the cut-line, tied with Will Zalatoris at nine under.

John Huh leads by two strokes after the first round of the Wyndham Championship, shooting a career-low nine-under 61 in his first trip around Sedgefield Country Club on Thursday.

With seven birdies, one eagle and no bogeys in his round, Huh had his game working from all areas. According to Data Golf's strokes gained stats, the American was the second-best in the tee-to-green category (5.29 strokes gained), third in approach shots (3.25) and sixth in putting (3.21).

Speaking to the media after his round, Huh said he did not feel like he was playing his best, but he is glad to be in such a strong position after entering the week on the fringe of the FedEx Cup Playoffs.

"It’s kind of strange," he said, "because I wasn’t really feeling great with my game and I shoot my career low – it’s kind of weird. 

"Sort of mixed feelings, but I’ll take this any day. I was able to take advantage of a good break and good shots, that’s all I can say."

Russell Henley carded his first bogey of the tournament but still managed to double his lead at the Wyndham Championship on Friday. 

Seeking his first PGA Tour win in four years, Henley shot 64 in the second round and sits at 14 under par for the tournament. 

That left him four strokes up on Rory Sabbatini (64), Webb Simpson (65) and Scott Piercy (66) heading into the weekend in Greensboro, North Carolina. 

Starting on the back nine at the Sedgefield Country Club, Henley bogeyed number 12, his third hole of the day, before reeling off four consecutive birdies from 14 through 17.

Three more birdies coming home after the turn solidified his edge as he eyes his first win since the 2017 Houston Open. 

Henley's 126 matches the lowest 36-hole score posted on tour this season along with Stewart Cink at the RBC Heritage. 

Tokyo Olympics silver medallist Sabbatini had a bogey-free day to match Henley's round, while Simpson remained near the top of the leaderboard thanks in part to an eagle at the fifth. 

Simpson's success is no surprise, as he has finished in the top three at the Wyndham the last four years after winning it in 2011. 

Tyler Duncan had the best round of the day with a 62 that left him five shots back at nine under along with Justin Rose (65) and Brian Stuard (66). 

Among other notables, Bubba Watson (69) and Adam Scott are 10 strokes back at four under, one shot better than the cut line. 

Masters champion Hideki Matsuyama (69) missed the cut by a stroke, while former world number one Luke Donald (67) finished at one under and two-time major winner Zach Johnson fell short at even par along with defending tournament champion Jim Herman. 

Also finished for the week-end are Padraig Harrington (76) at two over, Rickie Fowler (72) at three over and Charl Schwartzel (73) at seven over. 

Fowler's missed cut means his season is over, as he will not make the FedEx Cup playoffs for the first time in his career. 

Two players who were tied for second after Thursday's opening round, Michael Thompson and Ted Potter Jr., also missed the cut after slumping to 74 and 77, respectively.