Patrick Cantlay threatened to claim the most remarkable of victories at the Valspar Championship, but had to settle for second as Adam Hadwin secured his maiden PGA Tour title.
Hadwin began the final round with a four-stroke advantage, but the Canadian was made to work for his breakthrough success as Cantlay - playing only his second tournament since November 2014 - produced a stunning final-round charge.
A former amateur world number one who was tipped for greatness when he turned professional in June 2012, Cantlay suffered a stress fracture in his back the following year and has barely featured since.
If his extensive injury troubles were not enough to deal with, the 24-year-old American suffered personal tragedy last February when he witnessed the death of close friend and caddie Chris Roth following a hit-and-run accident.
Yet after returning to competitive action at Pebble Beach four weeks ago, Cantlay looked capable of triumphing on Sunday as, after starting the day four behind Hadwin, he got to within one of the lead thanks to a run of five birdies in six holes from the ninth.
Although Cantlay bogeyed the 15th, the duo were level on 14 under when Hadwin found water off the tee at the next and dropped two shots.
Both men then parred the penultimate hole, before a four at the last proved enough for Hadwin to triumph as his rival failed to get up and down from a greenside bunker.
Hadwin, who is set to postpone his upcoming honeymoon after securing a place in the Masters courtesy of his win, told Golf Channel: "I don't know what to say right now.
"I fully expected Patrick to make that putt [for par on 18]. I just wanted a chance to win coming up the last and I had that chance."
Dominic Bozzelli and Jim Herman shared third on 12 under following respective rounds of 67 and 68, while Tony Finau (64) was a stroke further back and 2016 champion Charl Schwartzel (68) finished five off the pace in sixth.