Defending champion Sam Burns holed a 32-foot putt at the second extra hole to score a dramatic playoff victory over Davis Riley in the Valspar Championship.
The two 25-year-old Americans had finished locked together at 17-under in the Florida event - Burns shooting a closing 2-under 69 and Riley a 1-over 72 - and couldn't be separated after trading pars at the first playoff hole, the 18th.
But on the second extra hole at the Copperhead Course, the par-4 16th, Burns seized the day by rattling in a stunning long-distance birdie putt, his ball doing a twirl around the hole before dropping into the cup.
Riley couldn't respond, leaving Burns to match Paul Casey's feat (2018-2019) of winning the event in successive years.
Sunday had started with Riley two clear of Matthew NeSmith but he suffered a huge blow at the fifth hole when making a triple-bogey eight.
Burns, who had started three behind, kept bogeys off his card thanks to some impressive putting and looked to have control of the tournament when teeing off at the 17th hole with a two-shot lead.
But he pulled his iron into sand and, after finding the fringe with his bunker shot, had to hole a nine-foot putt for bogey.
That dropped him to 17-under and he was joined there by Riley when the 54-hole leader hit the shot of the day at the 17th, a beautiful iron to six feet which he holed for a birdie two.
Both Burns and Riley had chances to birdie the last after good approaches but after an exchange of pars, the tournament went to a playoff.
It could have been a four-man shootout but Justin Thomas (70) and NeSmith (71) came up a shot shy.
Thomas' hopes of reaching the playoff number of 17-under were undone when he drove into a bunker at the last and could only splash out. He did well to get up and down from 89 yards for par but it left him a shot back.
Halfway leader NeSmith, who played in the final group with Riley, kept his victory ambitions alive with a birdie at 17.
His 34-foot attempt for another at 18 wouldn't drop but at least he had the consolation of securing his best-ever finish (tied third) on the PGA Tour.
England's Matt Fitzpatrick made it four top 10s in his last five PGA Tour starts by finishing in a tie for fifth with left-hander Brian Harman. Both closed with 68s.
"It's just hitting me. Man, it's just crazy," said Burns.
A reflective Riley said: "Very solid week. A lot to build on. No, I can't hang my head about anything.
"I played a lot of good golf and unfortunately I didn't have my best stuff today and I stumbled on hole 5 today and that kind of cost me.
"But at the end of the day it's a great week to build on and I'm looking forward to the next start."
Burns one of the PGA Tour's hottest players
With victory at the Valspar, Burns now has three PGA Tour wins in the last year.
Two of them have come in this event while be also took the silverware in October's Sanderson Farms Championship.
Only two other players have three strokeplay wins on the PGA Tour over that same time frame.
They are Augusta hero Hideki Matsuyama (Masters, Zozo Championship and Sony Open) and Patrick Cantlay (Memorial, BMW Championship and Tour Championship).
The victory also takes Burns up from 17th to 10th in the world rankings, his highest ever position.
Next step? The Majors. Burns has yet to finish better than tied 29th (PGA Championship in 2019).
However, on his current form, Burns looks an interesting contender at next month's Masters even though he'll be making his debut at Augusta National.
Fate of the favourites
Collin Morikawa and Viktor Hovland both had the chance to reach World No.1 this week.
But Morikawa dropped back to tied 68th after a poor weekend (74-73) while Hovland had to settle for tied 33rd after never getting in contention.
Dustin Johnson's underwhelming play continued as he finished tied 39th.
Justin Thomas was the only elite player to make the top 10 although Xander Schauffele should have joined him but dropped to tied 12th after taking a double bogey six at the last.