US veteran Kenny Perry seized a two-shot lead over world number one Tiger Woods on Saturday with a six-under 64 in the third round of the $7.5-million US PGA Tour Championship.

Perry would still need help to claim the US tour's FedEx Cup playoff series title - and the $10-million bonus that comes with it - but he put himself in prime position to capture the series-ending event with an eight-under 54-hole total of 202.

Perry will be paired Sunday in the final group with Woods, who carded a 69 for 204.

Perry launched his round with four birdies to make up a deficit to overnight leader Woods, and stayed steady the rest of the way to put a third title of the season in his sights.

"Four birdies in a row puts you in a good mood is all I can say," Perry said. "That set the tone for the day."

The tone was set for Woods when his 12-foot birdie attempt at the first failed to drop. He drained birdie putts of 20 and 55 feet, but missed a string of opportunities from inside 15 feet.

"I got fooled a few times there," Woods said of the deceptive slope and grain of the greens.

Woods came into the event atop the FedEx Cup series standings, and will claim the series title and the bonus dollars with a victory, regardless of where anyone else finishes.

Perry must win, and have Woods finish in a three-way tie for third or worse to capture the series crown.

It's possible that Perry - or someone else - could win the title and Woods claim the playoff crown.

"I'd much rather just win the tournament, and the FedEx Cup will take care of itself," Woods said. "As of right now, I'm two back and have an opportunity to win the tournament. And that's what I'm going to focus on tomorrow."

Phil Mickelson (66) and Sean O'Hair (70), were tied for third on 206. O'Hair arrived at 17 tied with Woods, but found the water with his tee shot en route to a double-bogey.

It was a further stroke back to Ireland's Padraig Harrington (71) and Steve Marino (67).

Perry said he was looking forward to playing with Woods, offering a lighthearted challenge to the world number-one.

"Here I am at 49, I'm still trying to beat him," Perry said. "I have fun with it. He'd better bring his 'A' game is all I've got to say."

Perry jumped out to a quick start on Saturday on a morning when the tee times were moved up because of the threat of inclement weather.

Woods's miscues on the green prevented him from responding.

Woods missed three birdie opportunities from inside 12 feet on the front nine, bogeyed the seventh from a fairway bunker and saved par from a greense bunker at the par-five ninth.

"It was amazing how I had about four or five putts today that the grain was going up the hill, and I didn't know which one to play," Woods said. "Do I play the grain or do I play the slope?

"Just one of those days where I happened to be in some interesting little spots."