Patrick Cantlay upstaged Jon Rahm and Justin Thomas as a final-round 65 earned him a one-shot win at the Zozo Championship.
The final day at Sherwood Country Club was billed as a head-to-head shoot-out between world No 3 and overnight-leader Thomas against world No 2 Rahm, but it was Cantlay who prevailed as the star final pair faltered over the back nine.
There was a further blow for Rahm at the end when, after the birdie putt he needed to force extra holes lacked the required pace and drifted right of the cup, Thomas holed a four-footer for a closing three that prevented the Spaniard from dethroning Dustin Johnson as world No 1.
Cantlay wasted little time in getting on the birdie trail, making three in the first four holes and then holing from 30 feet for another at the sixth, and he made another good putt for a three at the ninth after an errant tee shot cost him a bogey at eight.
With Rahm, Thomas and Lanto Griffin struggling to create birdie chances behind him, Cantlay kept the pressure on and vaulted three clear of the field when he picked up a further four shots in five holes from the 11th, and another looked likely as he had lob-wedge in hand from the fairway for his third to the par-five 16th.
But he opened the door for Rahm and Thomas as he chunked his approach and pulled it left, his ball hitting a tree and dropping into a buried lie in the rough, from where he needed three more to get down for bogey.
Cantlay regrouped to close with a pair of cast-iron pars to post 23 under par in the clubhouse and Rahm needed just one birdie over the final two holes to match that having recovered from back-to-back bogeys at 12 and 13 with a good four at the long 16th.
However, the Spaniard was a little too aggressive with his 15-foot putt on the penultimate green, and too tentative with his 20-footer at the last to leave Cantlay celebrating his third PGA Tour title, and his first since winning The Memorial in June last year.
Rahm needed a win or solo second place to replace the absent Johnson at the top of the world rankings, but Thomas denied him that honour when he ended a tough day on a bright note, converting from four feet for his fourth birdie of the round, with the previous three all coming over the first six holes.
Thomas trailed Cantlay by one when he short-sided himself with a tugged tee-shot to 15 and couldn't get up and down, and his attempt to hit the 16th green in two ended badly as he blocked his second into water, although he did well to pitch to five feet and rattle in the putt to save par.
The overnight leader just missed out on a two at the 17th, and his closing birdie capped a 69 and ensured joint runner-up honours with Rahm, with Bubba Watson gearing up for a stab at a hat-trick of Masters titles with a tie for fourth following a pair of 68s over the weekend.
Rory McIlroy vowed to cut out the mistakes when he arrives at Augusta National for the Masters next month, finishing on 15 under and outside the top 15 despite making a career-best 29 birdies over 72 holes.
And there was little was Tiger Woods (74) and long-time rival Phil Mickelson (78) to cheer on the final day as they finished fourth-last and second-last respectively.