Japan's Satoshi Kodaira birdied the third extra hole to beat South Korean Si Woo Kim in a playoff at the RBC Heritage in South Carolina to earn his first PGA Tour win.
After each player parred the 18th hole twice to start the playoff, it was Kodaira who drained a 24-foot birdie putt at the par-3 17th at Harbour Town on Hilton Head Island to secure the biggest win of his career.
Kodaira, who began the day six shots behind overnight leader Ian Poulter, mixed seven birdies with three bogeys in regulation for a five-under 66 that left him at 12 under and set the stage for his first PGA Tour win in only his sixth start.
"This is what I was dreaming about," said Kodaira, who tied for 28th at last week's US Masters.
"I didn't think it would come this quickly."
Cameron Smith and Rod Pampling were the highest-finishing Australians, carding a five-under-par overall total of 279.
Kim was cruising along after making three front-nine birdies but struggled with his putter over a dismal closing stretch that included a trio of bogeys over a six-hole stretch, the last coming at the par-3 17th.
Kim, who won his third PGA Tour title last year at The Players Championship, still had a chance to secure the win in regulation but failed to convert a seven-foot putt at the par-4 18th.
"I felt like I had a lot of chances to win, especially on the back nine and with none of them falling it kind of set me back and also made me nervous," Kim said through a translator.
"I wish some of those putts would have dropped."
Luke List (72) could have been in the play-off but missed a 10-foot birdie putt at the last and settled for a share of third with Bryson DeChambeau (66).
DeChambeau, who held the halfway lead but imploded in the third round to sit seven shots back, mixed two bogeys with seven birdies, including one at each of the final four holes.
Englishman Poulter, competing in his sixth PGA Tour event in as many weeks, ran out of gas on the back nine as he carded five bogeys over an eight-hole stretch en route to a four-over 75 that left him three shots back.
World No.1 Dustin Johnson (67) carded his lowest round of the week but it was too little, too late as he finished seven under and five shots back.
The final round ended much earlier than usual as tee times were pushed ahead and players went off split tees in threes in a bid to avoid afternoon thunderstorms that were expected.