Justin Leonard, the 1997 British Open winner who last won a US PGA event in 2008, fired a four-under par 67 on Saturday to share the 54-hole lead at the Tampa Bay Championship.
The 40-year-old American stood alongside countryman Kevin Streelman and South African George Coetzee on six-under 207 after three rounds at the $5.5 million event.
"I was pretty focused on controlling what I could, which wasn't much. It was pretty tough out there," Leonard said. "I hit a lot of great drives, made a few greens and hit a few putts and suddenly I'm leading the golf tournament."
Americans Jim Furyk, Ben Kohles and Tag Ridings share fourth with Australian Greg Chalmers on 208 with England's Luke Donald and Americans Bryce Molder, Jordan Spieth, Brian Harman and Shawn Stefani on 209.
Leonard, who seeks his 13th tour title overall and his first since the 2008 St. Jude Classic, hit all 13 fairways off the tee and credited that accuracy with his jump to the top.
"That's a big thing on this golf course," Leonard said. "There's not a whole lot of rough but if you are in the rough, you are near some trees and have to manufacture something.
"Being in the fairways all day allowed me to be more aggressive with my shots."
Leonard birdied the par-4 second, then closed the front nine with back-to-back birdies. He added short birdie putts at the par-5 11th and par-4 12th holes before taking his lone bogey of the day at the par-3 15th.
Streelman is in his 153rd US PGA event with his career-best finishes being shares of third in 2011 at Puerto Rico and Mexico. He began the round sharing 31st place, seven strokes off the pace, but fired a 65 to move up.
The 34-year-old opened with a birdie, added another at the sixth and then began the back nine with three birdies in four holes, including the par-4 10th, par-5 11th and par-3 13th. He added a birdie at the par-3 17th and closed with a par.
Coetzee, 26, is playing his first US PGA event that is not a major tournament or World Golf Championships event.
"I'm just here to pick up experience," he said. "I'm not expecting to win. I just want to go out and have a good round on Sunday."
The Pretoria native began with a birdie, added another at the seventh and birdied the par-5 11th as well. He answered his lone bogey, at the par-4 16th, with a birdie at 17 to stay in a share of the lead.