Overnight leader Corey Pavin struggled to a 2-over 72 and is tied with Jose Coceres, who carded a 66 on Friday. The pair share fourth at 6-under-par 134.
Funk, who made his first Ryder Cup team after the PGA Championship two weeks ago, birdied the second hole when he rolled in a 22-footer. He added his second birdie two holes later when his 5-iron stopped 10 feet from the hole.
Funk made his move up the leaderboard with solid play midway through his back nine. At the 14th, Funk hit a 9-iron to 4 feet and converted the birdie try. He made it two in a row at the short 15th when his drive landed right of the green, pin-high. He chipped to 6 feet, sank the putt and took the lead at minus-8.
The 48-year-old moved two clear of the field at 17 when his pitching-wedge approach spun 5 feet short of the hole. Funk made that putt, but bogeyed 18 when he landed in the rough.
But Funk is happy to be playing in better form after missing the cut at the PGA and tying for 61st last week at the WGC-NEC Invitational.
'If I hit a couple of shots poorly, I feel like I'm hitting so many good ones that I can get this going,' said Funk. 'I was excited about going to the Ryder Cup, but I wasn't excited about how I was playing. I've got that 'where it's fun to play' feeling again.'
Johnson, who won this year's BellSouth Classic for his first tour victory, started on the back nine Friday and did not look like he would be sharing the lead at the halfway point.
He missed a 5-footer for par at No. 12, but came back to birdie the 13th, this time cashing in from 6 feet. Johnson missed the green at 15, but chipped to 3 feet and kicked in the birdie putt. He drained a 25-foot birdie putt at 18 to make the turn at 33.
Johnson hit a sand-wedge to 2 feet to set up birdie at the second, his second birdie at the hole in as many days. He got to 7 under for the tournament with a 5-foot birdie putt at four and joined Funk in first with a 16-foot birdie putt at the par-3 eighth.
Johnson is a tour rookie who has a few things going with him this week. Aside from his breakthrough win in Georgia, Johnson won the Envirocare Utah Classic on the Nationwide Tour this week last year.
'There is a trend in that for me,' said Johnson, the Nationwide Tour Player of the Year in 2003. 'I hope last year is a sign that this year will be good too.'
Kuehne, the tour's longest driver, first broke into red figures with a birdie at the third. He pulled his drive in the left rough, but got a wedge on it and rolled in the 20-footer.
He missed the green short with a 2-iron at the par-5 sixth, but chipped on and made birdie. He collected his second birdie in a row when he missed the fairway right at the seventh, but hit a lob-wedge to 2 feet for his third birdie of the front nine.
Kuehne once again was able to make birdie from the rough, this time at the par-5 13th. He pulled another drive and laid up 75 yards short of the green. His approach lipped out of the hole and Kuehne tapped in for birdie.
The 28-year-old recorded his final birdie of the round at the driveable, par-4 15th. Kuehne pulled his 2-iron and landed 15 feet from the pin, albeit in the left rough. He chipped on then tapped in for birdie and a 65.
'I played pretty solid golf,' said Kuehne. 'I hit 15 greens, but the three greens I missed were all fringes, so I was able to putt everything. I really had a low stress round, which was nice.'
Joey Sindelar, this year's Wachovia Championship winner, shot a 3-under 67 and is tied for sixth place with Bob Burns (70), Kirk Triplett (67), Esteban Toledo (66), Tom Byrum (66) and Robert Gamez (66). That group is tied at 5-under-par 135.
American Ryder Cup captain Hal Sutton missed a 4-foot par putt on his 18th hole Friday to shoot a 1-over 71 and miss the cut by a stroke at 2-over-par 142.
Among the other notable players who will not be around on the weekend are: Nick Price (143), two-time U.S. Open champion Lee Janzen (143) and Fred Couples (149).