Gary Woodland beat Chez Reavie on the first playoff hole to win the Waste Management Phoenix Open at TPC Scottsdale.
Woodland started his final round with a bogey-free five-under 30, but ran into a snag early on the back nine with two bogeys.
Fowler rolled in from six feet at the 13th and drained an 18-footer at the 16th, before converting a birdie at the 17th and picking up a 10-foot gain at the par-four last.
Woodland won the hole and the tournament with a par and Reavie, who had birdied the final two holes to force the playoff, made bogey.
Ollie Schniederjans and Brendan Steele tied for third place at 15-under.
The 47-year-old, who had slipped to 49 in the world rankings at the start of the week, delighted the gallery at the 16th with a 20-foot putt and made it three birdies in a row by holing from the edge of the green at the next. "I spent some time with Pete Cowen", he said. I still got to get more comfortable with the little things we're working on. Phil Mickelson, who has won three Phoenix Open titles, finished 2 under par Sunday to end the tournament at 14 under, and Jon Rahm finished 1 over Sunday to finish at 12 under for the tourney. "I mean, I really had it going".More news: Here's the First Trailer for Melissa McCarthy's New Comedy
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Fowler was red hot early in his round, making four birdies on his first six holes and, while he slowed on the back nine, it was enough to move to the top of the leaderboard. "It obviously was a long year for us, but I'm very happy to be holding him and to be where I'm at today". Then came the disaster at 16, where - well, watch and cringe as he missed a tap-in, posted a double, and fell completely out of contention.
Hadley, a Web.com Tour graduate, continued his scintillating season with his fourth top-five finish. Well, until he shot 73 on Sunday.
Rickie Fowler holds the 54 hole lead by the slightest of margins.
Don't forget about players like DeChambeau, Schauffele and Berger. "I think that was kind of the biggest letdown". I told myself "if I can make two more birdies, that would give me a good chance to win".
With tears in his eyes, he added: "Just wanted her to know I still love her".
"I was putting good, I was feeling good, I was just waiting for that moment and it just never happened".