This makes Kim the youngest victor in Players Championship history, breaking the record set by Adam Scott (then 23 years old) in 2004. He won his first Web.com tour event in 2015 (the Cleveland Open) to become the tour's second-youngest victor in its history.
Adam Scott has made an 11th-hour bid for a top-10 finish at the Players Championship with a back-nine charge during the final round at TPC Sawgrass. Now it's about getting closer to that level each time on the course.
That's a mind-boggling number given the conditions (hot and fast) and the field closing in quickly around him.
Despite enduring a run of poor form entering the week, the 21-year-old looked poised beyond his years while capturing the season's so-called "fifth major".
QUOTABLE: "I feel like I'm still dreaming that I won this tournament". He earned a card at age 17, but he could not become a PGA Tour member until he turned 18 the following June. The PGA Tour has signed a 10-year extension with the title sponsor of the FedEx Cup.
I'm not saying he's the South Korean Tiger Woods or anything, but this week was not an accident. Kim did it methodically on Sunday.
Maybe the most impressive thing from Kim on Sunday is how he neer seemed rattled by the moment.
"It's been a tough 18 months to be honest". When you shoot 68-69 on the weekend at the Players Championship, you deserve those fruits for the labor. "You just don't give shots away". It just shows you how good a player he is and how cool and calm he is. Great golfers are like that.
He famously lost in playoffs at the 2012 Masters Tournament and 2015 Open Championship, but says he has tried not to let the near misses bother him.
Kim sank a 24-foot birdie putt at the par-4 seventh to seize the lead and sank an 18-foot birdie putt at the par-5 ninth to reach 10-under for a two-stroke advantage. The juice was running, and he'd left himself nothing. We are glad you asked. "I actually had the better lie of the two". Off the putting surface and with little green to work with, Kim chipped the ball to two feet. "That just showed a lot of class". He trailed by just two shots after the first round, shooting a 3-under 69 with three birdies, an eagle and just two bogeys. "I had a good week, I played nicely, wasn't spot on today, but happy with second". You have to take your hat off. Then there were the likes of Jordan Spieth, Rory McIlroy, Jason Day and Phil Mickelson. Oh, did we forget to mention that he's 21 years old?
"It was a big shock to the system to hit one of those nasty shanks when I've hit it as good as I have all week, but the fourth shot was pretty special, from one of the worst shots I've ever hit to one of the very best", he said. "So I can hit aggressively and I wasn t as nervous".
" I wish I had taken a couple of decent opportunities there at the end, it definitely could have been lower, but if you asked me if I'd have taken 71 before teeing off today I would have for sure. I'm enjoying my golf and hopefully this is a stepping stone for this year".
After his final-round performance, Kim might have been the only one surprised. With a new silky-smooth swing teamed with a crafty short game, Kim could be a force on the PGA Tour for years to come. History at this tournament says there are plenty more to come.