Sung Kang earned his first PGA Tour victory with a final-round 67 at the AT&T Byron Nelson in Dallas.
Meanwhile Pádraig Harrington rounded off a solid week with a fine closing round of 65, leaving him on 15 under par for the tournament and in a share of 12th place.
The three-time Major winner warmed-up as the week progressed, posting rounds of 69, 69, 66 and then a 65 - which included seven birdies and a solitary bogey.
31-year-old winner Kang, who matched the Trinity Forest course record with a 61 in the second round, had to complete 27 holes on the last day after a severe weather delay hit round three.
He entered the final round with a three-shot lead over Matt Every but a sluggish start saw him even par through the first seven holes before birdies through holes eight to 10 got him back on track.
The hot play continued across the back nine when a 23ft birdie on the par-four 15th — the second of three straight birdies — gave Kang the outright lead.
The South Korean closed out 23 under for the tournament, two shots ahead of Americans Every and Scott Piercy, who ended the tournament completely bogey-free.
In a press conference after the tournament, Kang said the win felt “amazing”.
Asked about a telephone conversation with his father in South Korea, where he was heard to say “I did it”, he added: My dad gave me a lot of support when I was young and sent me over to the US when I was 15 and gave me a lot of opportunity to learn from good pros.
“It helped me a lot, giving me support.”
Speaking of his closest challengers, he added: “These guys are unbelievable. Scott Piercy and Matt, making so many birdies on the front. I was like OK, I’m not even going to care about this anymore. Whatever they do, they do. I was just working on my game.”
Masters runner-up Brooks Koepka, who is looking to defend his US PGA Championship later this week, finished fourth at 20 under, while Scotland’s Martin Laird ended in a tie for 35th at 10 under.
Collated final scores & totals in the AT&T Byron Nelson (USA unless stated, par 71):
261 Sung Kang (Kr) 65 61 68 67
263 Matt Every 65 65 67 66
264 Brooks Koepka 65 66 68 65
265 Scott Piercy 67 69 63 66
267 Rory Sabbatini (Sk) 67 65 68 67, Kiradech Aphibarnrat (Th) 69 68 66 64, Peter Uihlein 69 71 63 64, Matt Jones (Au) 65 70 65 67, Tyler Duncan 64 66 70 67
268 Justin Harding (Za) 66 73 64 65, Sebastian Munoz (Co) 69 66 65 68
269 Pat Perez 67 71 67 64, Carlos Oritz (Mx) 69 69 66 65, Doug Ghim 69 66 66 68, Nicholas Lindheim 70 69 62 68, Padraig Harrington (Ie) 69 69 66 65
270 Stephan Jaeger (De) 69 66 67 68, Kramer Hickok 65 73 66 66, Vaughn Taylor 69 67 68 66
271 Shawn Stefani 65 72 64 70, Henrik Stenson (Se) 67 69 66 69, Jonas Blixt (Se) 65 70 70 66
272 Daniel Berger 66 72 66 68, Denny McCarthy 63 77 65 67, Hideki Matsuyama (Jp) 67 70 68 67, Brady Schnell 72 67 64 69, Cameron Tringale 69 69 69 65, Thomas Pieters (Be) 70 66 69 67
273 (a) Davis Riley 68 69 66 70, Sepp Straka (At) 69 71 68 65 Joey Garber 68 69 66 70, Morgan Hoffmann 70 68 65 70, Nate Lashley 67 73 67 66, Jordan Spieth 68 67 67 71
274 Kevin Na 69 68 67 70, Scottie Scheffler (a) 67 69 69 69, Alex Noren (Se) 70 68 67 69, Russell Henley 71 67 69 67, Zack Sucher 67 68 68 71, Martin Laird (Ld) 67 66 70 71, Cheng-Tsung Pan (Tw) 66 70 69 69, Cameron Davis (Au) 67 69 70 68
275 Bud Cauley 70 69 64 72, Ryan Palmer 68 69 71 67, Roberto Diaz (Mx) 66 67 69 73, Beau Hossler 67 66 70 72, Aaron Wise 69 69 66 71, David Lingmerth (Se) 71 68 65 71, Harris English 68 71 68 68, Curtis Luck (Au) 71 67 66 71, Russell Knox (Ld) 68 69 68 70, Johnson Wagner 72 68 67 68
276 Michael Thompson 66 68 71 71, Bill Haas 68 70 69 69, Kevin Tway 70 66 70 70, Rafael Cabrera-Bello (Es) 70 70 67 69, Troy Merritt 65 74 68 69, Brandon Harkins 68 72 69 67
277 Brian Stuard 67 72 70 68, Abraham Ancer (Mx) 69 71 69 68, J.J. Spaun 66 70 72 69, Keith Mitchell 66 73 66 72
278 Daniel Chopra (Se) 72 67 69 70, Branden Grace (Za) 69 70 66 73, Seth Reeves 66 70 70 72, Patrick Reed 70 68 67 73
279 Dylan Frittelli (Za) 68 72 69 70, Tom Hoge 64 75 70 70
280 Ollie Schniederjans 68 69 70 73, Brian Gay 68 72 69 71, Ryan Moore 69 70 68 73