Kyle Stanley carded a six-under 64 to grab a two-shot lead after the opening round of the Tour Championship, as Jordan Spieth, Justin Thomas and Jon Rahm made decent starts.
Stanley, who started the season-ending event 22nd in the FedEx Cup standings, holed seven birdies and just one bogey at East Lake Golf Club on Thursday.
The American made a red-hot start with four straight birdies from holes three through six - including a 37-foot putt to pick up a stroke at the fourth - before his only blemish arrived at the par-four eighth.
Stanley birdied holes 12, 15 and 16 to move to six under and he is now projected to finish second in the FedEx Cup as it stands.
Webb Simpson, Daniel Berger, U.S. Open champion Brooks Koepka and Paul Casey carded 66s to be tied for second.
Spieth remains the projected winner of the $10million prize after a solid three-under 67 to open the event in Atlanta, Georgia.
The American three-time major champion is one of five players - alongside Thomas, Rahm, Dustin Johnson and Marc Leishman - who could secure the overall title with a victory.
US PGA Championship winner Thomas endured a mixed round with six birdies and three bogeys to be alongside Spieth and Rahm in a tie for sixth.
Rahm made an eagle at the sixth thanks to a 21-foot putt but needed birdies at the final two holes to card his 67. Russell Henley and Gary Woodland are also at three under.
World number one Johnson made a decent start, going through bogey-free for his two-under 68.
Coming off a wire-to-wire win at the BMW Championship, Leishman had no such luck, the Australian posting a 71 to be tied for 21st in the 30-man field.
Another contender, Rickie Fowler, struggled to a 73, as did Spaniard Sergio Garcia.