Sweden's Henrik Stenson put himself in pole position to win the Tour Championship, FedEx Cup and USD10million bonus for the second time in three years after the first round in Atlanta.
Stenson had the opportunity to shoot the seventh 59 in PGA Tour history when he played the first 12 holes at East Lake in eight under par thanks to six birdies and an eagle.
And although the Ryder Cup star played the last six in one over par, an opening seven-under-par 63 was one better than his first round in 2013 and gave him a two-shot lead over England's Paul Casey, with Rory McIlroy and Open champion Zach Johnson a shot further back.
As one of the top five in the FedEx Cup standings coming into the season finale, Stenson knows his first victory of the season will see him claim the eight-figure bonus on top of the first prize of USD1,485,000.
"It was great," the 39-year-old told Sky Sports 4. "I'm coming here with a purpose and trying to play my best golf of the year and I managed to do that so I am very happy.
"It's still early doors, it's going to be a long week and a lot of players trying to chase me down but I got the start I wanted."
Stenson made a flying start with birdies on the first three holes and, after picking up another shot on the sixth, reduced the 600-yard ninth to a three wood off the tee, four-wood approach and eagle putt from 45 feet.
Asked if he was thinking of shooting 59 after birdies on the 10th and 12th, Stenson added: "Not so much. I was more trying to think about giving myself opportunities and I didn't really give myself good chances on 13, 14 or 15.
"The finish here is not easy. I think I made all my scores on the front nine when I won here in 2013. The last three holes you are pretty happy if you can play them in par every day."
World number one Jason Day, Masters and US Open champion Jordan Spieth, Rickie Fowler and Bubba Watson are the other players who control their own destiny, Spieth faring best with a 68, Day and Fowler shooting 69 and Watson level par.
Day, who was 101 under par for his last seven events, matched Stenson's opening three birdies at the first three holes, but t he US PGA champion then drove out of bounds on the fifth and ran up a triple-bogey seven.
Casey, who has not played in the Tour Championship since 2010 after suffering from injuries and a loss of form, told Sky Sports 4: "It's great to be back. I have been through a lot since then so it's wonderful to be among the top 30 with a chance of winning the FedEx Cup.
"It's a course I really like, very classic. It sets up very well for my game; you have to put yourself in good position off the tee, a high ball flight helps and these greens are as quick as Augusta, and that's what I like."
McIlroy admitted on Wednesday that the bonus money "l uckily, doesn't sort of mean much to me any more" but insisted he was determined to add the FedEx Cup title to his CV after finishing second to Billy Horschel 12 months ago.
The world number two was one over par after six holes and admitted he needed the "spark" provided by holing from 12 feet for birdie on the difficult seventh hole.
"I felt like I was playing pretty well but to hole a putt like that down the hill gave me a lot of confidence," McIlroy said. "I feel like I am swinging well. I hit a lot of shots pretty close today and am going to have to continue to do that over the week to have a chance."
Former Open champion Louis Oosthuizen withdrew after 13 holes with a hamstring injury, reducing the field to 28 after Jim Furyk was forced to miss out due to a wrist problem.