Updated

Keegan Bradley fired a six-under 64 Thursday to stroke lead after the opening round of the Tour Championship.

Bradley, a tour rookie, has won two events this year, including the PGA Championship at nearby Atlanta Athletic Club.

World No. 1 Luke Donald parred the 18th hole after a brief weather delay to post four-under 66. He was joined in second place at East Lake Golf Club by Jason Dufner, who lost to Bradley at the PGA Championship, and Chez Reavie.

Rain started to fall after the final groups made the turn. With two groups remaining, officials blew the horns to take players off the course due to threatening weather in the area.

After a 29-minute delay, the final two groups returned to the course to complete their rounds.

Charles Howell III, Matt Kuchar, Adam Scott, Hunter Mahan and Jason Day share fifth place at minus-three.

The players are not only jostling to win this championship, but also the FedExCup. Webb Simpson, who leads the race for the FedExCup, bogeyed the final hole to shoot one-under 69, which left him tied for 16th.

Several players are also trying to earn a captain's pick for the Presidents Cup. U.S. captain Fred Couples has stated he will take Tiger Woods with one pick, meaning there is one spot available to the remaining American players.

Bradley and Dufner are among those fighting for that last spot. Bradley is 20th on the points list, while Dufner is 14th. Brandt Snedeker and Bill Haas, Nos. 11 and 12 on the points list, are among those tied for 10th at two-under 68.

"I was joking earlier that the cliche is to say that I'm not thinking about it, but literally probably every third hole or maybe even less it pops into my mind," Bradley admitted. "I say it every time, I really want to be on the team, but I want to earn my way onto the team just like I'm going to have to. If the captain and assistant captains think I've done enough to get on the team, they're going to pick me. And if they don't, that's totally fair, too."

The top international players that are at East Lake and battling for one of Greg Norman's picks to the Presidents Cup are Aaron Baddeley and Vijay Singh. Baddeley is among those tied with Snedeker and Haas at minus-two, while Singh is in last place at four-over 74.

Bradley started his round with a hole-out birdie from a greenside bunker on the par-three second. After making four straight pars, the PGA Champion rolled in an 11-footer for birdie on the seventh.

The 25-year-old Bradley faltered to a three-putt bogey on No. 8, but quickly bounced back with a two-putt birdie on the par-five ninth.

Around the turn, Bradley sank a six-foot birdie effort on the 12th to get to three-under. After making a five-foot birdie attempt on No. 14, Bradley two- putted for birdie at 15 to gain the lead at minus-five.

Bradley pushed his lead to two strokes with a four-foot birdie putt on the 17th. He parred the last.

"It was a good day out there. I just felt comfortable right from the start," Bradley stated. "I made a bunker shot on the second hole, which kind of got me calmed down, and it just seemed to be easy today, and it seems to be easy when you play good golf. When you play bad golf, it seems hard. It was just a good day."

Donald traded a birdie for a bogey from the first. He poured in three birdies in a four-hole span from the eighth to get to three-under. After three consecutive pars, Donald birdied the 15th. He parred the last three holes to share second.

Dufner birdied three of the first four holes to quickly move to minus-three. He ran off 10 straight pars from the fifth before posting his final birdie on the par-five 15th.

"Good start to the day, three-under through four, so great way to start a tournament. Threw in a birdie late on the back," said Dufner. "Played okay, scored really well. Any time I was in trouble, I was able to make a par. A little disappointed with how I drove the ball today."

Reavie had the most inconsistent round. He birdied the fourth and sixth, but gave both strokes back with a double-bogey on the seventh. Reavie birdied three of five holes from the eighth to get within one of the lead.

The 29-year-old from Arizona faltered to a bogey on the 13th, but responded with birdies on the 15th and 16th to end at minus-four.

NOTES: Bradley's 64 matched a career-low on the PGA Tour...Jim Furyk, the reigning Tour Championship winner and FedExCup champion, failed to qualify...The top five on the points list -- Simpson, Dustin Johnson, Justin Rose, Donald and Kuchar -- can all win the FedExCup with a win this week.