Dustin Johnson was winless in his last nine starts with only two top-10 finishes, then beat Spieth on the first playoff hole.
Spieth didn't sink it this time, but negotiated the break perfectly and left it 18 inches from the hole, close enough to save par.
3 - Rory McIlroy finished in a tie for 34th, fully 15 shots behind Spieth and Johnson.
"Jordan's a tough competitor", Johnson told CBS' Dottie Pepper in the immediate aftermath. Both golfers shot 13-under on the day.
"That's what I feel like is happening now".
As Johnson made a couple of bad swings, Fowler caught up with him on the front nine itself.
"I feel the game's finally back in form like it was leading into the Masters", Johnson said in a greenside interview. "This was the first one I've really had to work at. Getting a win here gives me a lot of confidence going into next week and the rest of the play-offs".
Dustin Johnson shot a 65 on Sunday, including three birdies on the back nine.
Wesley Bryan said the choice of hole effectively made the play-off a "long drive contest", while Luke Donald jokingly compared his length off the tee to that of Johnson.
Johnson now leads the FedEx Cup standings over Spieth.
Johnson's ascent in the rankings has been steady, highlighted by winning the 2016 U.S. Open, the first major tournament victory of his career.
"I didn't lose this tournament", Spieth said. I was a little disappointed yesterday after the way I played. "This week I did that - I finally got back". I'm much more mentally sharp right now than I have been all year, which is great, even though I am making silly errors.
Suri began the day two shots behind Horsey, but the Englishman dropped a shot at the first, while Suri birdied the second, third and fourth to take control. Just get the putting more consistent. It's very hard holding a lead on a hard golf course when the guy you're playing with goes bogey-free and doesn't even really sniff a bogey and shoots four-under. "But no surprise, either". Jhonattan Vegas was within two shots after playing the scoring holes.
Wie has been plagued by injuries throughout the year. It ended up being the right distance, I guess. "Just a matter of trying to go out there and put the best possible rounds together and see where that leaves me".
World No. 2 Hideki Matsuyama missed the halfway cut for the second time this season on Friday, unable to recover from an uncharacteristically poor first round at the Northern Trust.