(CNN) -- Veteran Jim Furyk produced the round of the day at the Tour Championship in Atlanta after carding a score of 64 at East Lake.
The American birdied six of the first nine holes to record an outward 29 as he raced through the field.
Furyk won the FedEX Cup $10 million prize two years ago and looked to have an incredible opportunity to record a 59 after hitting seven birdies in the first ten holes.
He also claimed birdies at the 15th and 17th but bogeys at the 13th, 16th and 18th left him just two shots clear at the top of the leader board.
England's Justin Rose shot a 68 to move into second place on six-under-par.
The joint overnight leader hit five birdies to remain in contention following his opening round of 66.
But World No.1 Rory McIlroy remained in pole position to claim that $10 prize for overall winner of the playoffs after producing his 10th consecutive sub-70 score.
McIlroy sank a 25-foot eagle putt on the 16th to ensure he finished with a round of 68 and leave him four shots off the lead at halfway.
The Northern Irishman was joined on three-under-par by Americans Robert Garrigus and Zach Johnson after both players hit rounds of 69.
But Tiger Woods, who shot an opening round 66 to share the lead with Rose, struggled to produce a repeat performance.
Woods, whose last win came at July's AT & T National, could only manage a 73 to leave him on one-under-par, a setback to his challenge to McIlroy for the playoffs title.
Masters champion Bubba Watson moved into contention on five-under-par alongside Bo Van Pelt, with Matt Kuchar and Dustin Johnson a shot further back.
Last year's money list winner Luke Donald of England shot a 69 to finish level par at the halfway stage, while his compatriot Lee Westwood was 28th out of 30 on five-over-par following a disappointing round of 73.