Even in July of previous year, Tiger dropped out of the top 1,000 in the golf world rankings.
Woods shot one-over par 71 to win by two shots from Billy Horschel, having led by three shots coming into the final round.
"You know, I've explained throughout the year that I just didn't know whether - when this would ever happen again", Woods said.
For those that take just a passing interest in golf, the last time they saw Woods would have been following his DUI arrest in May 2017.
Jack Nicklaus, the man widely considered the greatest golfer of all time and whose record of 18 major titles Woods is still chasing, said he was "happy" and "proud".
Woods won more than five years after winning the 2013 WGC-Bridgestone Invitational by seven shots to lavish a fifth PGA Tour victory upon a fantastic season that seemed chirpy at the time.
"All of a sudden it started hitting me that I was going to win the tournament, and I started tearing up a little bit".
And only a birdie on the 72nd hole from Rose prevented Woods from claiming the overall FedEx Cup title as well, Rose two-putting from 25 feet on the par-five 18th to claim the £7.6million bonus in nerve-racking fashion.
All year, Woods had shown signs of his old self.
Justin Rose, who entered the day three shots behind Woods, made a key birdie on 18 to win the FedEx Cup title - a four-tournament playoff with a $10 million prize to the victor.
Two weeks before the Tour Championship, Rose had climbed to No. 1 in the Official World Golf Ranking after his playoff loss in the BMW Championship, but Johnson reclaimed the top spot by a slim margin with his Sunday surge in Atlanta.
"To get 80 is a pretty damn good feeling", Woods added.
A week before the Masters in April, Woods announces that he requires back surgery, forcing him to miss the year's opening major for the first time since 1994. He would be flying out a few hours later towards France for the Ryder Cup.
He came into the final day of the tournament - the last of four FedEx Cup play-off events - with a three-shot lead over Rose and Northern Ireland's Rory McIlroy, who faded from contention with a four-over 74 to finish on five under in tied seventh. He carded six birdies on the first seven holes, which even drew the attention of National Basketball Association star Stephen Curry, who tweeted at Woods, "I want whatever you had for breakfast this morning!"