WHITE SULPHUR SPRINGS, July 6, 2013 (AFP) - Wagner made seven birdies, the last of them on a 12-foot putt at the par-3 18th, against a lone bogey to complete 54 holes on 14-under 196, two strokes ahead of countryman Jimmy Walker, who fired a bogey-free 64 at The Old White.
Sweden's Jonas Blixt was third on 200, one stroke ahead of Australians Matt Jones and Stephen Bowditch and US teen Jordan Spieth, who at 19 is trying to become the youngest US PGA Tour champion since 1931.
Wagner, who opened with a 62 on Thursday, missed the cut in six of his past seven starts and withdrew from the other after the first round.
But thanks to some extra work with his coach last month, he was poised to capture his fourth career US PGA title after triumphs at the 2008 Houston Open, the 2011 Mayakoba Classic in Mexico and last year's Sony Open in Hawaii.
"I had a little 'Boot Camp' with my coach two weeks ago and got my game back to where it was heading into Hawaii two years ago," Wagner said. "I'm feeling really good right now. I'm able to shape the ball. It's really clicking."
When the last pairing teed off, there were 19 players within two strokes of the lead and 36-hole leader Matt Every stumbled with three bogeys in the first four holes, setting the stage for Wagner to seize command.
Wagner opened with a 14-foot birdie putt, sank an eight-foot birdie putt at the par-3 third and tapped in for a birdie at the fifth to reach 11-under and grab a two-stroke lead.
Blixt, who opened with back-to-back birdies, added an eight-foot birdie putt at the seventh to reach 10-under, which put him in a share of the lead after Wagner took a bogey at the seventh.
At the ninth hole, Wagner found a fairway divot but blasted onto the green and sank an 18-foot birdie putt to reclaim the lead alone and then began the back nine with a birdie as well.
Wagner added a 20-foot birdie putt at the par-5 12th to move three strokes in front and, after Walker reached the clubhouse only one stroke off the pace, closed with a 12-foot birdie at the par-3 18th to move two ahead of Walker.
"It has been over a year (that) I have struggled," Wagner said. "Luckily, I'm having a great week this week."
Walker, seeking his first PGA title, shared third this year at Pebble Beach to match his best career PGA showing from the 2010 Texas Open.
Blixt won his only PGA title at last year's Frys.com Open. While he has not cracked the top 10 in a US PGA event this year, he finished second last month at the European Tour's Swedish Masters.
Bowditch has only one top-10 finish in four seasons on the US PGA Tour.
Spieth, a former world amateur number one who turned professional last December, would become the fourth-youngest winner on the all-time US PGA list and the youngest since Ralph Guldahl won the Santa Monica Open 82 years ago.
Spieth, who has won enough money to secure a US PGA Tour spot in 2014, needs a victory to gain membership this year and be eligible for the season-ending playoffs that open next month.
Leading scores on Saturday after the third round of the $6.3 million US PGA Greenbrier Classic (USA unless noted, par-70):
196 - Johnson Wagner 62-70-64
198 - Jimmy Walker 69-65-64
200 - Jonas Blixt (SWE) 66-67-67
201 - Matt Jones (AUS) 69-66-66, Jordan Spieth 67-67-67, Steven Bowditch (AUS) 65-67-69
202 - Pat Perez 71-65-66, Bill Haas 68-67-67, Rory Sabbatini (RSA) 70-65-67, Lee Dong-Hwan (KOR) 66-68-68, Tag Ridings 65-69-68, Tommy Gainey 62-71-69
203 - Gary Woodland 69-70-64, Morgan Hoffmann 69-67-67, Bill Lunde 66-66-71
204 - Nick Watney 72-67-65, Cameron Percy (AUS) 71-68-65, Bryce Molder 71-67-66, Tim Petrovic 69-68-67, Scott Stallings 70-67-67, Brian Stuard 71-66-67, David Lingmerth (SWE) 71-66-67, Louis Oosthuizen (RSA) 67-68-69, Ted Potter 69-66-69, Ben Curtis 67-66-71, Russell Henley 67-65-72