Rory McIlroy birdied two of his last four holes but still finished 71st for putting in the Frys.com Open in California.
A three under 69 left the Co Down man tied for 26th on nine under par at Silverado Country Club in Napa, where Argentina's Emiliano Grillo birdied the second playoff hole to beat Kevin Na and win on his debut as a fully exempt PGA Tour player.
World No 3 McIlroy holed once from off the green and had just 27 putts to squeak into the positive column for Strokes Gained Putting on the final day.
However, he was 71st for Strokes Gained Putting overall and despite am improved final day performance, he may well feel he has work to do to be 100 percent competitive in the Turkish Airlines Open in a fortnight, the first of three Final Series events he plans to play to try and retain the Race to Dubai title.
After a a poor wedge cost him a shot at the fourth, he wedged to four feet to set up his first birdie of the day at the fifth and then fired another wedge to two feet at the sixth to get into the red.
He holed from 20 feet at the short 11th to go two under, but drove out of bounds right at the next and did well to scramble for a bogey after a 76 yard approach to 10 feet.
A towering 200-yard iron to three feet at the 15th was converted for another birdie, and he two-putted from 55 feet at the long 16th to pick up another shot before parring in.
Just two weeks after holing a 25 footer on the 72nd hole to win the Web,com Tour Championship and his PGA Tour card, 23-year old European Tour regular Grillo made a birdie four from 23 feet at the 18th to get to 15 under and then birdied the same hole when it again to beat Na in at the second extra hole to secure his maiden PGA Tour win and a move to 36th in the world.
A graduate of the IMG Academy's class of 2011 alongside PGA Tour stars Jordan Spieth, Patrick Rodgers, Daniel Berger and Justin Thomas, Grillo drained a nine footer for a birdie four after a third trip up the par-five 18th having lipped out with a three footer for victory there on the first extra hole.
“You say Masters, I can’t believe it,” said Grillo, who closed with a three-under 69 and eventually earned $1.08m and a place in the Masters for his win.
“This is awesome. There is no words to put in to explain this. This is the greatest moment of my life golf-wise.”
It was also a great show of character by Grillo., who has an Irish manager, as he had a chance to win the Puerto Rico Open on the PGA Tour in March missed a short putt for victory went on to lose in a five-way playoff.
Having missed a three footer for victory on the first extra hole. a lesser player might have collapsed. But he made the most of a second chance, sinking a nine-footer for birdie on the second hole of sudden death to beat Na, who was making six at best after opting to hit driver off the deck for his approach smother hooking it into trouble in the trees left.
Grillo was in sand off the tee and had hit a perfect lay up before Na's risky approach backfired.
The Argentinian then hit super third to nine feet and watched as Na flew the green and eventually left him with two putts for the title.
“I couldn't sleep for a week,” Grillo said of his miss in Puerto Rico. “It was one of the most painful times of my life, that's for sure.”
On his birdie at the second extra hole, he added: “I stayed positive. I learned a lot from the one in Puerto Rico. My caddie asked me was I 100 percent and I said yes. I want to win it. You know how they say it, third time is charm.
“Most important than the win was the putt on the last hole. Made me believe that I can hole putts on the last hole. You know, I did it then; did it twice today on the last hole basically. You know, makes you believe you can do it. That’s huge.”
Grillo began the day two shots behind Brendan Steele, who imploded with five bogeys in the last six holes for a four-over 76 and trailed home 17th.
Na, who birdied four of his last six holes, including a four on the par-five 18th, forced a play-off on 15 under par
The pair finished a shot ahead of Americans Thomas (69) and Jason Bohn (70) and Tyrone Van Aswegen of South Africa (68).
Meanwhile, the The PGA TOUR announced last night that Safeway is the new title sponsor the Frys.com Open. The five-year agreement runs through 2020 with the PGA TOUR event remaining at Silverado Resort and Spa for the duration.