Aaron Baddeley, battling for a spot on the Presidents Cup International team, birdied four of his final six holes to seize a share of the lead after the third round of the Tour Championship. Australia\'s Baddeley shot a six-under 64 on the East Lake golf course Saturday at the $8 million tournament which serves as the culmination of the US PGA Tour\'s playoffs. Baddeley was joined at the top of the leaderboard by American Hunter Mahan who posted a four-under 66. They are tied at nine-under-par 201. \"For me, it\'s a motivator,\" Baddeley said of his bid to play well enough to persuade International captain Greg Norman to select him for the Presidents Cup.\"I want to play good. I want to be on that team, so I knew I had to play well this week. It\'s time to bear down. I got some good work done on Tuesday and Wednesday, so I was ready for Thursday.\" The event features the top 30 players from a season points race trying to win a title along with the $10 million prize going to the overall FedEx Cup points leader. Also on offer is a last chance to stake a claim to spots on the Presidents Cup US and International teams. Mahan clinched his spot on the US team last week. Baddeley, of Melbourne, is in a struggle with several others to grab one of Norman\'s two captain\'s picks. Baddeley, who eagled the par-four fourth, also posted four consecutive birdies from the 13th hole on Saturday.Mahan rolled in a 20-foot birdie putt on the last hole for his 66 to keep his chances at the top money prize alive. Aussie Jason Day and South Korea\'s KJ Choi were two shots adrift of Baddeley and Mahan. Both Day and Choi rebounded from ragged starts Saturday to shoot 69 and 70. At the beginning of the week, Mahan didn\'t think he had much of an opportunity to collect the $10 million top prize. World number one Luke Donald is the only one of the top five in the standings that still remains in contention. Mahan is also right there. \"I honestly didn\'t think that was a possibility,\" Mahan said. Donald shot a 70 and was only three shots behind along with American Bill Haas (69) at six-under 204. Phil Mickelson is also within striking distance of the leaders after shooting a three-under 67 to reach 205.\"I feel like the first three rounds, I had three possibilities of 63, 64 that I turned into 68, 69,\" Mickelson said. \"If I can just not do that and keep it where I feel the round should be, I think I can make a run tomorrow.\" The points race to decide the FedEx Cup winner remained muddled. As many as five players moved to the head of the list Saturday, but nothing will be decided until Sunday. Webb Simpson is currently first on the list after he birdied his final hole to move into a tie for 15th in the stroke play tournament at one-under 209. If Simpson finishes in the top 12, he could collect the $10 million prize even if Mahan wins the tournament.\"It\'s kind of weird,\" Mahan said. \"I could still win - I could play flawless golf tomorrow, win by five - and finish fifth in FedEx Cup points. I could finish 10th in FedEx Cup points. It\'s one of those things where you can\'t even worry about it just because you can\'t do the math that fast.\"