GAINESVILLE, 1 Aug 2015, (AFP) - Merritt, a 29-year-old American ranked 180th in the world, birdied the first five holes and finished with 11 birdies against a lone bogey in the third round at Robert Trent Jones Golf Club.
That left Merritt level with countryman Kevin Chappell atop the leaderboard on 14-under 199 after 54 holes with US star Rickie Fowler one stroke back.
Fowler is coming off wins at the Players Championship in May and the Scottish Open three weeks ago while Merritt and Chappell each seek their first PGA title.
"The big thing is we put ourselves in contention and that was the goal," Merritt said. "I hit the ball really well and got a lot out of it. I think we're going to have a decent chance."
The old tournament record of 62 was shared by Americans Hunter Mahan and Anthony Kim from 2009 at Congressional Country Club and Nick Watney from 2011 at Aroniminik.
Tournament host Woods sprayed shots all day on his way to a 74 to finish on 208, sharing 42nd after starting the day sharing fifth.
Woods, a 14-time major champion who has not won a major since the 2008 US Open, is on a two-year win drought after struggling with injuries and swing changes the past two seasons.
Leading scores after Saturday's third round of the US PGA Quicken Loans National (par-71, USA unless noted):
199 - Troy Merritt 70-68-61, Kevin Chappell 64-68-67
200 - Rickie Fowler 67-65-68
201 - Jason Bohn 67-67-67, Kim Whee (KOR) 68-66-67, Charles Howell 67-67-67, David Lingmerth (SWE) 68-65-68
202 - Carl Pettersson (SWE) 70-68-64, Bill Haas 67-71-64, Justin Rose (ENG) 66-71-65, Ryo Ishikawa (JPN) 63-68-71
203 - Steven Bowditch (AUS) 68-68-67, Danny Lee (NZL) 67-67-69, Ollie Schniederjans 66-69-68
204 - Vaughn Taylor 70-70-64, Brendan Steele 70-68-66, Cameron Tringale 68-69-67
205 - Andres Romero (ARG) 69-69-67, Justin Thomas 66-71-68, John Peterson 67-70-68
206 - Brian Davis (ENG) 70-70-66, Jason Kokrak 71-68-67, Colt Knost 71-67-68, Steve Wheatcroft 65-73-68, Shawn Stefani 71-67-68, Ernie Els (RSA) 64-74-68, Gonzalo Fernandez-Castano (ESP) 66-71-69, Adam Hadwin (CAN) 67-70-69, Ricky Barnes 69-68-69, Justin Leonard 64-72-70, Brice Garnett 69-65-72, Pat Perez 67-67-72