Joaquin Niemann became the first Chilean to win on the PGA Tour as he claimed the A Military Tribute title at the Greenbrier in West Virginia by six shots.
The 20-year-old took a two-stroke lead into the final round and barely faltered as he secured victory with a six-under-par 64.
An emotional Niemann, who at 20 years, 10 months and eight days, is younger than both Seve Ballasteros and Rory McIlroy when they won their first Tour titles, told Sky Sports: "It's just amazing.
"I've been thinking about this my whole life since I started playing golf, so it's unbelievable. I still can't realise what happened today. I just need to calm down a little bit and just celebrate.
"It's just crazy. I'm really happy for all the support, my family, my coach. It's just crazy."
American Tom Hoge's 65 secured second place after compatriot Richy Werenski bogeyed the last hole and had to make do with a share of third with compatriots Brian Harman, Harris English and Nate Lashley.
Niemann carded birdies at the fifth and eight and although he dropped a shot at the ninth, he picked up three in the next four holes to get to 19 under.
Four ahead of the field with four to play, he hit a wayward tee shot at the 15th and saw his lead eroded slightly by a bogey four, only to restore his advantage with a solid birdie putt at the 16th.
Both Niemann and playing partner Werenski found greenside bunkers with their second shots at the par-five 17th, but the former recovered to card a four while the latter two-putted to slip a shot further back. The Chilean then finished in style with a lengthy putt for a two at the last to cap a comprehensive victory.
Down the field, Norwegian Viktor Hovland's 64, his 17th consecutive sub-70 round on the tour, was enough to claim a share of 10th place.