Brian Harman made a dramatic 72nd-hole birdie four to deny world No 1 Dustin Johnson and Pat Perez and snatch his first win since 2014 in the Wells Fargo Championship. 

The 30-year old left-hander came to the par-five 18th tied for the lead on nine-under with Johnson (67) and Perez (68) when sliced his second behind a grandstand, took a free drop and then flubbed his pitch to 28 feet.

A playoff looked likely for the Georgia native, who has three-putted the 15th to fall one behind Perez and Johnson, who was seeking his fourth successive win.

But he dug deep, birdied the 17th from five feet to draw level, then made that unlikely 28 footer at the last and post a 68 for 10 under par total.

Only 22-year old Basque superstar Jon Rahm could send the tournament into sudden-death with an eagle three.

"It's surreal," Harman said after Rahm could only par the last for a 71 and settled for fourth on eight under. 

"I three-putted that 15th hole and knew it was going to be tough to birdie those last couple. But I stuck to my game plan and did the best I could." 

Harman’s only previous win came at the John Deere Classic three years ago but he took his latest chance to seal his place in the Masters and that’s the mission now facing West Waterford’s Seamus Power, who was left to rue another poor weekend.

The 30-year rookie went into the last two rounds just a shot off the lead on five under par but ended the week tied for 49th on one-over after closing rounds of 77 and 73.

Power is now 141st in the FedEx Cup from which the top 125 keep their cards but while he picked up just $18,950, the man from Tooraneena has shown that his good golf is good enough to snatch a win.

It was also a case of what might have been for Graeme McDowell and Shane Lowry at the Wilmington venue.

Four shots behind leader Patrick Reed overnight, McDowell found himself tied for the lead on seven under when birdied three of his first seven holes.

But the Ulsterman, who was bidding for his first PGA Tour win for 15 months, saw his title chances evaporate with bogeys at the 14th, 17th and 18th, eventually signing for a final round 72 and a share of 18th on four-under.

Tied for 19th starting the day, Lowry had to birdie three of his last seven holes to shoot a level par 72 and finish tied 24th on three-under.