Atlanta - World number one Justin Rose is projected to end the season as the PGA Tour's No 1 after signing for a 66 on day one of the season-ending Tour Championship. 

Rose teed up on the East Lake course in second place on the FedEx Cup standings but is projected to leapfrog American Bryson DeChambeau after the American struggled Thursday in the elite 30-player field. 

DeChambeau, 25 and the winner of the opening two playoff series events, struggled with the driver on the East Lake course. 

No such concern for Rose. His 66 was his lowest Tour Championship starting round since shooting a 66 in 2012. 

"I am really happy with my round today as I played fantastically, if I'm honest," said Rose in his first round as World No 1. 

"I felt like it was a day that I could have gone low. The birdie-birdie finish made me feel like I got enough out of the day to make me happy." 

Rose heads to the second round just a stroke behind the leading duo of Rickie Fowler and Tiger Woods. 

Past East Lake winner Rory McIlroy was clearly disappointed after letting a two-shot lead after six holes slip away. 

He eventually signed for a 67 to share fifth place. 

"I played well and it was a great start to be four-under through six holes," he said. 

"It was just unfortunate I just didn't keep it going. But if I keep swinging and hitting the ball like that and giving myself chances, I should be right up there at the end of the week." 

Keegan Bradley, who captured the recent BMW Championship, shares last place in the 30-player field with Phil Mickelson and Australia's Marc Leishman in posting three-over par 73s.

Leaderboard:

65 - Rickie Fowler, Tiger Woods

66 - Gary Woodland, Justin Rose (ENG)

67 - Justin Thomas, Tony Finau, Rory McIlroy (NIR)

68 - Jason Day (AUS), Jon Rahm (ESP), Xander Schauffele, Paul Casey (ENG)

69 - Kyle Stanley, Webb Simpson, Brooks Koepka, Dustin Johnson, Tommy Fleetwood (ENG)

70 - Cameron Smith (AUS), Francesco Molinari (ITA), Aaron Wise, Bubba Watson (USA)