J.T. Poston fired an eagle and six birdies in an eight-under par 62 on Sunday to seize his first US PGA Tour title at the Wyndham Championship as overnight leader An Byeong-hun faded to third.
Poston, a North Carolina native who delighted a big group of friends and family at Sedgefield Country Club in Greensboro, North Carolina, made a big move with a five-under front nine that included his eagle at the par-five fifth.
Three more birdies coming in were enough to give him the victory on 22-under par 258.
"I don't think I could have drawn it up any better," said Poston, who became the first player since Lee Trevino in 1974 to win a 72-hole stroke-play event on the US tour without a bogey or worse on his card.
"I probably haven't had that many bogey-free rounds this year," Poston said. "To be able to do four in a row is pretty special, and finish it off with a 62 on Sunday is pretty awesome."
Webb Simpson, another North Carolinian whose first PGA Tour title came at the Wyndham in 2011, shook off a slow start to card a five-under par 65, rolling in a birdie at 18 for a 21-under par total of 259.
South Korea's An had held at least a share of the lead after each of the first three rounds, but his bid for a first US PGA Tour title ran into trouble with his first bogey of the week, at the par-five 15th.
He arrived at 18 needing a birdie to force a playoff and was in the trees off the tee.
He rammed a birdie attempt 10 feet past the hole and closed with a bogey for a 67 that dropped him a stroke behind Simpson on 260.
Poston, who started the day three shots off An's lead, trimmed the deficit with three birdies and his 13-foot eagle at the fifth.
He added birdies at the 10th and 13th -- where he landed his second shot less than three feet from the pin -- to reach 21-under and took a one-shot lead with a birdie from a greenside bunker at 15.
An fell a further stroke back with his first bogey of the tournament at 15, where he drove into deep rough and took a penalty drop and unlike on Saturday was unable to salvage par.
He called that bogey "the killer" and although An birdied the 16th he couldn't come up with another birdie to force a playoff.
"I just ran out of juice," An said.
In the final tournament of the US tour's regular season, Patton Kizzire and Andrew Landry finished well enough to make the three-event playoffs.
With the top 125 in the FedEx Cup rankings qualifying for the series, Patton Kizzire played his way in from number 129 and Andrew Landry from 134th -- both earning a chance to tee it up at the Northern Trust at Liberty National next week.
J.T. Poston on the way to a final-round 62 and his first US PGA Tour title in the Wyndham Championship
South Korea's An Byeong-hun reacts after a putt attempt at 18 in the final round of the Wyndham Championship, where he finished third