NEW ORLEANS, April 28, 2014 (AFP) - The 22-year-old South Korean finished at 19-under-par 269 to beat out Americans Andrew Svoboda and Robert Streb.
"I'm very excited and very happy," said Noh, who was making his 78th career start on the North American tour.
Svoboda (69) and Streb (70) closed with birdies at 18 to move into a tie for second place at 17-under, while Jeff Overton (70) finished in fourth at 16-under.
Robert Garrigus (64), Erik Compton (68) and Charley Hoffman (71) shared fifth at 14-under 274, a shot ahead of Justin Rose (68), Keegan Bradley (75) and Tommy Gainey (71) at the TPC Louisiana course.
Noh has two previous international victories, winning the Midea China Classic in 2008 and the Malaysian Open in 2010.
He used precision iron shots and clutch putting to claim the championship in New Orleans. Noh becomes the fifth Korean-born player to win on the Tour, joining KJ Choi, YE Yang, Kevin Na and Bae Sang-Moon.
After saving par on the par-three 17 he tapped in for another par on 18.
Noh began the fourth round with a two-shot lead, but quickly gave up one of those strokes with a bogey on his opening hole. It marked his first bogey of the tournament.
He followed his first hole bogey with six consecutive pars before making birdie on number eight. He also birdied the 10th to regain a two-shot lead.
His approach on the 13th hit the flag stick leaving him with a short birdie putt to reach 19-under.
"It was a bad lie a little bit, a little bit of downslope and a little bit of sand at the bottom, so it was a little tricky shot," Noh said about his shot that hit the flag.
Svoboda and Streb both made birdie on the last to finish at 17-under and put a little pressure on Noh, but he would par those final two holes to close out his maiden win.
Scores after Sunday's final round of the $6.8 million US PGA Tour Zurich Classic (par 72, USA unless noted):
269 - Noh Seung-Yul (KOR) 65-68-65-71
271 - Andrew Svoboda 64-68-70-69, Robert Streb 67-66-68-70
272 - Jeff Overton 67-68-67-70
274 - Robert Garrigus 73-69-68-64, Charley Hoffman 68-67-68-71, Erik Compton 66-68-72-68
275 - Justin Rose (GBR) 71-67-69-68, Tommy Gainey 71-66-67-71, Keegan Bradley 69-66-65-75
276 - Paul Casey (GBR) 71-68-64-73, Peter Hanson (SWE) 65-69-71-71, J.B. Holmes 71-65-69-71, Bud Cauley 71-68-66-71
277 - David Toms 73-68-67-69, Ben Martin 62-67-73-75
278 - Stuart Appleby (AUS) 67-72-70-69, Rory Sabbatini (RSA) 69-72-69-68, Mark D. Anderson 72-65-70-71, Cameron Tringale 73-69-66-70