Diminutive left-hander Brian Harman rolled in a 30-foot birdie at the final hole to win the Wells Fargo Championship on Sunday and end Dustin Johnson's quest for his first victory since withdrawing from the US Masters.

With Johnson watching on TV in the clubhouse at Eagle Point in Wilmington, North Carolina, Harman stroked a beautiful putt and erupted in delight when it dropped into the cup.

He carded 68 to finish at 10-under-par 278 for his second PGA Tour victory, one stroke ahead of fellow Americans Johnson and Pat Perez.

World number one Johnson, playing for the first time since falling down stairs on the eve of the Masters a month ago, was seeking to become the fifth player in PGA Tour history to win at least four consecutive starts. 

Graeme McDowell's challenge fell away in the final five holes, three frustrating bogeys forcing him to settle for a level-par 72 and four-under overall after he at one point shared the lead.

It was still a fine weekend for the Northern Irishman in the company of such a stellar field, and Shane Lowry will also be satisfied with a good weekend's work

He followed up yesterday's brilliant 68 with a level-par round that left him one shot behind McDowell for the tournament in a tie for 24th. The Offaly man had to scramble t make the cut on Friday, but recovered impressively in North Carolina.

Seamus Power shared the clubhouse lead with Billy Hurley III afte his second round but the Waterford man slipped down the leaderboard over the weekend.

He signed off with a 71 to finish tied 49th on one-over.