The 23-year-old PGA Tour rookie from Texas looked destined for defeat after slicing his drive almost out-of-bounds at the second extra hole, the par-four 10th at Sedgefield Country Club.
But Reed’s ball stopped barely one yard in bounds and he took advantage of his lucky break by conjuring up a piece of magic with his second shot, threading a seven-iron that somehow avoided the trees and finished within seven feet of the hole.
“It was the best shot of my life, that’s for sure,” said Reed, whose caddie – and wife – Justine measured the shot at 167 yards.
“When I got the signal the ball was out of bounds my heart sank. I pulled my hat down and I was so frustrated and sad. If I didn’t close that out and win it I would have been heartbroken.”
But when Reed got word from other marshals that the ball was safe, his spirits soared.
“I felt I was back playing T-ball. The ball was so far above my feet that it almost felt like I was taking a baseball swing.
“The lie was fine. There was a little bit of dirt, a couple of pieces of grass, twigs, a couple of spiders, basically anything you’d find in a wilderness.
“The problem was the tree I had to go under. The tree trunk was right there and I had to hit the ball dead straight from a baseball lie. It’s hard for me to do that, because I play draws.
“I knew it was going to be do or die. I had to make a great golf swing and to pull it off meant everything.”
The vanquished Spieth was certainly impressed: “It was one of the best shots I’ve ever witnessed,” said Spieth. “I walked over to his ball (because) I wanted to see what he had to do and he didn’t have much.
“I didn’t think he could hit the ball that high and stop it from that lie.”
Spieth gave Reed a sporting thumbs-up, but it still wasn’t over, because Spieth had a sharply-breaking 10-foot birdie putt that shaved the right edge of the hole but didn’t drop.
That opened the door for Reed, who made no mistake with his birdie putt to capture his first tour victory, worth $954,000 and the Sam Snead Cup.
Reed’s heroics prevented Spieth from becoming the youngest two-time winner on tour in more than a century. Nevertheless, the 20-year-old, who won last month’s John Deere Classic, continued his emergence as one of the game’s rising stars.
The play-off was a rollercoaster of emotion for Spieth, who seemed destined for defeat at the first extra hole after pulling his drive into the woods.
He had no choice but to pitch his second shot back to the fairway and a poor third shot left him 26-feet above the hole, from where he defied the odds and sank the par putt.
Reed still had a chance to win with a seven-foot birdie attempt, but his putt was poor and the hole was halved, setting up even more drama at the next hole.
Earlier, Reed (66) and Spieth (65) finished regulation tied at 14-under-par 266. They both made tap-in pars at the 72nd hole to finish two strokes ahead of fellow Americans John Huh, who bogeyed the final two holes, and Brian Harman.
(Reporting by Andrew Both, editing by Simon Evans in Miami)