Henrik Stenson shot a seven-under-par 63 to earn the outright lead after day one of the Tour Championship in Atlanta tonight.
Six birdies and an eagle at the ninth saw Stenson make the early running at East Lake to earn a slender two-stroke advantage on England's Paul Casey heading into Friday's session.
World number two Rory McIlroy, meanwhile, sits three shots off the pace after an opening-round 66, comprising six birdies and two bogeys.
The Northern Irishman is level with Open champion Zach Johnson on four-under, while two-time Major winner Jordan Spieth is one of six players two strokes back.
Casey's compatriot Justin Rose is level par after his opening 70.
