* First to win without bogey since Trevino in 1974
* Beats Simpson by one stroke at Sedgefield
* Overnight leader An rues drive on 15th hole (Adds quotes, details)
By Andrew Both
GREENSBORO, N.C., Aug 4 (Reuters) - North Carolina native J.T. Poston became the first player in 45 years to win a PGA Tour event without dropping a shot when he beat Webb Simpson by one stroke at the Wyndham Championship on Sunday.
Not since Lee Trevino at New Orleans in 1974 had a player negotiated 72 holes without a bogey en route to victory.
Poston stormed out of the pack, claiming his first tour victory in style with an eight-under-par 62 at Sedgefield Country Club.
Born less than 100 miles away in Hickory, and buoyed by enthusiastic support, Poston finished at 22-under 258.
Fellow North Carolinian Simpson (65) birdied the last for second place, while South Korean An Byeong-hun (67) bogeyed the par-four 18th for third, two shots behind.
An had a 60-foot birdie putt that would have forced a playoff. He gave it a good run, his ball touching the edge of the cup but rolling 10 feet beyond. He missed the comeback attempt.
"Any win out here on tour is a dream come true but to do it here in Greensboro, an hour-and-a-half from where I grew up, is something I never could have imagined," said 26-year-old Poston.
"I've got so many friends and family that are here, coming in from all over the place. The celebration's going to be a lot of fun."
Poston said a quick session with his instructor on Monday led to his blemish-free tournament.
"He gave me one little tip and it clicked right away. I mean, bogey free is great.
"The course was easy enough to where if you hit fairways you could attack some pins, and my iron play was really solid all week and today I made some puts and was able to get that low one in there."
An also played bogey-free for 68 holes, before finally dropping a shot at the par-five 15th, where for the second day running his drive ended in long fescue rough, prompting him to take a penalty stroke.
"That 15 was very disappointing because I didn't hit that bad of a drive," said the 27-year-old, still winless on the PGA Tour.
"I think there was too much adrenaline going on. It wasn't a bad drive to end up where it was.
"I should have hit a two-iron maybe to stay in the fairway and to give myself a chance to go at the green but the bogey was definitely a killer. At the end I just ran out of juice I think."
Simpson birdied four of the last five holes for second. (Reporting by Andrew Both, editing by Pritha Sarkar/Peter Rutherford)