Jim Furyk had the round of the day at the Tour Championship in Atlanta, but Rory McIlroy's tenth successive sub-70 score put him back on course for a €7.5million jackpot this weekend.
Twenty-three year old world number one McIlroy sank a 25-foot eagle putt on the 16th in a second round 68 at East Lake.
With Tiger Woods, joint overnight leader with England's Justin Rose, struggling to a 73, McIlroy, winner on his last two starts, is now leading the race for the massive FedEx Cup play-off bonus again even though he stands joint seventh in the tournament at halfway.
On seven under par, Furyk leads the event by one from Rose after a 64 that included an outward 29 – in which he birdied five of the first seven holes and then almost pitched in for eagle at the long ninth.
Rose birdied the difficult short 18th for the second day running to edge a stroke in front of Bubba Watson and Bo Van Pelt, but after a double bogey and five bogeys, four of them in the last eight holes, Woods fell all the way to joint 12th.
McIlroy had a lucky break on the tenth, hooking his drive against a fence but being given a free drop because of ground under repair.
Woods resumed with an untidy bogey after pushing his approach to the first into a bunker and his birdies at the third and seventh both came after he had driven into more sand.
He missed the green at the next, fluffed a chip and double bogeyed, came back with a birdie, but then dropped more strokes at the 11th and 12th.
Furyk won the FedEx Cup €7.5million two years ago and looked to have a chance of a 59 when he had seven birdies in the first ten.
More came at the 15th and 17th, but there were also bogeys at the 13th, 16th and 18th.
"For me the back nine plays quite a bit tougher," the 42-year-old said. "I stumbled a bit again, but I've got myself back in the hunt.
"When I'm playing well I can play on any course and here there's more of a premium on keeping the ball in play."
Luke Donald shot 69 to stand level par and joint 16th, but, with a 73, Lee Westwood was 28th in the 30-man field on five over.