Japan's Hideki Matsuyama fought back to claim a two-shot victory on an eventful final day at the FedEx St Jude Championship.
Matsuyama, who took a five-stroke lead into the fourth round at TPC Southwind, looked as though he might throw the title away when, having picked up two birdies as he left the 11th green at 19 under par, he surrendered four shots in as many holes.
Officials spoke to the 32-year-old about a potential infringement over replacing a divot on the green on an earlier hole as the Japanese golfer headed to the 12th tee.
It clearly affected him as he bogeyed that hole before dropping another at the par-three 14th after finding water with his tee-shot, and he then double bogeyed the 15th to relinquish the lead.
Viktor Hovlund edged into the lead on 16 under par, but dropped a shot at the 17th to go level with Open champion Xander Schauffele, who had carded a blemish-free 63.
But Matsuyama responded with birdies at each of the last two holes to ease himself back to 17 under.
He told reporters following his victory: "I'm especially happy to be able to win one of the FedEx play-off series tournaments.
"I've tried hard for 10 years and it's a great feeling of satisfaction to finally be able to have done it."
World number one Scottie Scheffler was a further shot behind in fourth and fellow American Nick Dunlap, who started the day as Matsuyama's closest, yet still distant, challenger, finished in a tie for fifth with compatriot Sam Burns on 13 under.
In the process, Dunlap secured his place in the FedEx top 50 and next week's BMW Championship in Colorado.
Northern Ireland's four-time major winner Rory McIlroy carded a second successive 74 to finish nine over par for the tournament, but sits in fifth place in the rankings and will be joined at Castle Pines by Ireland's Shane Lowry, Scot Robert MacIntyre and Englishmen Tommy Fleetwood, Matt Fitzpatrick and Aaron Rai.
Justin Rose, however, failed to make the top 50 after following two rounds of 66 with back-to-back 71s.
