Waterford's Seamus Power has won the PGA Tour’s Barbasol Championship after a sudden death play-off.

The 34-year-old's victory over J.T. Poston on the sixth play-off hole at the Keene Trace Golf Club in Nicholasville, Kentucky was his first PGA Tour win on his 106th start.

Power carded a five-under par 67 to lead in the clubhouse on 21 under before third-round leader Poston parred his final hole to force a play-off.

Poston lost a healthy lead down the home stretch. His tee shot on the 15th was ruled out of bounds by several inches, leading to a double bogey. Poston then made a three-putt bogey at the par-3 16th, slipping to 21 under.

Power, 34, birdied the 18th to shoot a final-round 67 and force a play-off, and he chipped in for birdie on the first play-off hole to ensure it kept going, before his American rival rolled in from about 10 feet.

Both men parred the 18th again before moving to the ninth where Power’s tee shot on the par 3 found the greenside bunker but he got up and down to extend the play-off to a fourth hole.

That took them back to the ninth once more where the 2016 Rio Olympian came up a foot short for a birdie and the win.

The duo could not be separated on the fifth extra hole but Poston found the water as they played the 18th again, paving the way for Power’s par to be good enough for an epic victory.

It was the third lengthy play-off the tour has seen just in the past month. Harris English bested Kramer Hickok at the Travelers Championship after eight play-off holes, tying for the second-longest play-off in tour history. A week later, Cam Davis won the Rocket Mortgage Classic on the fifth play-off hole over Troy Merritt and Chile's Joaquin Niemann.

The win sees Power, who took up the game at West Waterford Golf and Country Club, move from 123rd in the FedEx rankings to the 60s and includes a full exemption through to the 2022-23 season and a spot at the Sentry Tournament of Champions, the Players Championship and the PGA Championship.

"It's [still] to sink in," Power said. "It’s been a bit of a struggle early in the season. I found a bit of form recently but this changes everything for me.

"Forever, I’ll be able to say I’m a winner on the PGA Tour. I couldn't be more proud...I just have too many people to thank. It’s unbelievable."

Power, who came into the week after five straight top-20 finishes including ties for eighth in the Rocket Mortgage Classic and John Deere Classic, does not earn a spot in next year's Masters despite the victory, since the tournament coincided with The Open Championship, where Masters rights were awarded.