Furyk finished 36 holes at 7-under 133 and is one stroke clear of first-round co-leader Justin Rose, who birdied the last for a 2-under 68.
This is the finale of the PGA Tour Playoffs for the FedExCup and the $10 million prize will be awarded on Sunday evening.
The two men who led the points race headed into the Tour Championship went in opposite directions on Friday.
Rory McIlroy, the leader in FedExCup Playoffs points based on his two Playoffs victories, shot a 2-under 68 and moved into a tie for seventh place at 3-under 137.
"I think first and foremost, I just have to try to think of my standing in this golf tournament, not really think about anything else," said McIlroy. "If it comes down to it on Sunday where I need to really know what I have to do for the last few holes, then of course if I have a decision to make between protecting my lead in the FedExCup or trying to win the golf tournament, I think I know what I'm going to choose."
Tiger Woods, a first-round co-leader with Rose and second in Playoffs points, notched four bogeys on the back nine Friday and signed for a 3-over 73. Woods, a two-time FedExCup champion, fell back into a tie for 12th at minus-1.
"I didn't hit it very good and definitely didn't putt well," said Woods. "It was a struggle all day. I'm still right there. This is a golf course that's playing tough."
The midway leader is no stranger to success in The Playoffs.
Furyk won this title in 2010 en route to victory at the FedExCup. He has not won on tour since this victory two years ago, although he was in position to win both this year's U.S. Open and Bridgestone Invitational, but coughed up both prestigious tournaments late on Sunday.
"I like the golf course to start with. I've had some good memories here," said Furyk. "Of course, I won here in 2010, so I've had some good events here. I'm comfortable on the golf course when I'm playing well. It suits my style."
On Friday, Furyk torched the front nine to the tune of six birdies.
He started with a 13-foot birdie at the first and two holes later, went on a birdie run. Furyk drained three straight 5-footers for birdie, including a spectacular birdie at five from 236 yards out.
At the seventh, Furyk knocked his approach inside a foot to set up a tap-in birdie. He recorded another little birdie, this time at the par-5 ninth and made the turn at 7-under par for the championship.
Furyk continued the great play with a 7-foot birdie at No. 10. That 7-under score through 10 holes was outstanding, but the 2010 FedExCup champion stumbled a bit on his way to the clubhouse.
At 13, Furyk drove into the first cut on the right side and couldn't reach the putting surface with his second. He made bogey on the hole, but got a stroke back with a birdie at the par-5 15th.
Furyk missed the fairway right at 16, the green left and walked off with a bogey. He got back to 8-under with a 14-footer for birdie at 17, but pulled his tee ball at the par-3 closing hole and made bogey.
"It was obviously a fun day," said Furyk. "To be able to write three on your card nine times in the first 11 holes was a lot of fun. I struggled to kind of keep that momentum going the last six holes, but I feel like I played a real solid round of golf."
This week could be a huge morale booster for Furyk with what lies ahead.
After two winless seasons on tour, Furyk was considered a mildly controversial pick when American Ryder Cup captain Davis Love III tabbed him to join the team that tries to get the Cup back next week.
"Really the opinions that matter to me are those of my captain and those of my teammates," said Furyk. "They know I have a lot of heart. I have a lot of grit, and that's what I'm going to do. But I've never felt like I have to justify myself. I've got 19 years behind me and a pretty good track record."
Masters champion Bubba Watson carded a 4-under 66 and is tied for third place with Bo Van Pelt, who had a 2-under 68 on Friday. The pair is knotted at 5- under 135.
Dustin Johnson, who has top 10s in all three Playoffs events, posted a 3-under 67 to move into a share of fifth with Matt Kuchar, whose 1-under 69 left him at 4-under par.
McIlroy was joined in seventh by Robert Garrigus and Zach Johnson, both of whom had 1-under 69s on Friday.
NOTES: The top five in Playoffs points could win the FedExCup with a victory this week. McIlroy and Woods are Nos. 1 and 2, but Nick Watney (third in points) is dead last, Phil Mickelson (fourth in points) is tied for 16th, and Brandt Snedeker (fifth in points) shares 10th...Furyk owns 16 PGA Tour wins and held the 36-hole lead in both this year's U.S. Open and Bridgestone Invitational.