HILTON HEAD ISLAND, S.C. (AP) -- Pan Cheng-tsung (潘政琮) took advantage of Dustin Johnson's back-nine struggles to win the RBC Heritage for his first PGA TOUR victory on April 21, local time.
The 27-year-old Pan, from Taiwan, closed with a 4-under 67 on Sunday at Harbour Town Golf Links for a one-stroke victory over Matt Kuchar. Pan finished at 12-under 272.
"It's still really hard for me to believe," he said. "I'm processing. My phone has been vibrating the last 10 minutes. I'm so happy I finally got it done."
Johnson, the third-round leader in his home-state event, had a 77 to tie for 28th at 4 under. He played a five-hole stretch in 7 over, making bogeys on Nos. 11-13 and double bogeys on Nos. 14-15.
Pan took the lead for good with a 9-foot birdie putt on the par-4 16th.
Kuchar closed with a 67.
Patrick Cantlay, Scott Piercy and Shane Lowry tied for third at 10 under. Cantlay and Piercy shot 69, and Lowry had a 70.
Pan headed to the practice range after the round to keep ready in case of a playoff, then raised his arms in triumph when told he'd won. He earned 500 FedExCup points, $1,242,000, and a PGA TOUR exemption through the 2020-21 season.
Pan won twice on the PGA TOUR Canada-Mackenzie Tour in 2015 when he turned professional. He's finished second twice in PGA TOUR events, once at the Farmers Insurance Open in 2017 and last year at the Wyndham Championship.
Johnson, the 20-time PGA TOUR winner, carried a one-shot lead into the final round and the South Carolina native seemed a strong bet to add the Palmetto State's only TOUR stop to his trophy case. But Johnson never found a rhythm early and lost all hope with his uncharacteristic drop off.
He had a birdie on the fifth to keep on top. Johnson's collapse started mildly with a bogey on the par-3 seventh hole. It took full flight on the back nine.
Johnson's frustrations were in full display on the par-4 13th when his approach went into the bunker, a foot or so from the wooden-board facing. He barely got it out and shook his head.
He flew his tee shot into the water on the par-3 14th to drop two more shots. Johnson added a second double bogey on the par-5 15th, a hole he had birdied the first three rounds.
Johnson waved to the stands on the 18th when he closed with a birdie.
Lowry, who had three bogeys over his final six holes Saturday to lose a lead he held much of the week, appeared to regain his earlier form with birdies on the second, fifth and sixth holes to take a two-shot lead. But a bogey on the straightforward, par-4 ninth -- Lowry had birdied it two of the first three rounds -- dropped him back. He stubbed a pair of chips on the 12th hole and took double bogey.
Lowry scratched back within a shot of Pan with a birdie on the 14th, but could come no closer.
Kuchar, the 2014 winner at Harbour Town, put together a charge of five birdies to tie Pan for the top. But a bogey on the par-3 17th following a tee shot into the bunker ruined his chances of a second tartan jacket.
Cantlay looked like a second strong weekend -- he went 64-68 his final two rounds at the Masters to tie for ninth -- might bring him victory as he tied for the top with consecutive birdies on the 14th and 15th holes. He had a chip from just off the green on the 18th for a tying birdie, but did not come close.