Robert Streb stayed steady at Sea Island on Saturday, stretching his lead in the PGA Tour RSM Classic to three strokes over two-time major winner Zach Johnson and Bronson Burgoon.
Streb had three birdies without a bogey in a 67 on the par-70 Seaside Course, where he won his only prior tour title back in 2014.
"It wasn't the greatest start," said the 33-year-old, who started the day with a two-shot lead but saw Colombia's Camilo Villegas briefly pull level before Streb notched his first birdie of the day at the eighth - where he stuck his approach shot within three feet of the pin.
Birdies at the 10th and 15th saw Streb finish 54 holes on 17-under 195.
Sea Island resident Johnson, chasing a 13th tour title but a first since he won the British Open in 2015, had six birdies and a bogey in his 65 for 198, where he was joined by fellow American Burgoon - who had six birdies and three bogeys in his 67.
Streb, who rallied on the final day to win here before, said that with the lead he'll just be "trying to keep doing what I'm doing."
"I don't think the wind's supposed to blow quite as hard tomorrow, so probably got to make a few birdies," he added. "(I'm) guessing a few guys will go low."
Johnson built momentum heading into Sunday with three birdies in his last five holes.
The 2007 Masters winner rolled in some formidable putts, starting with a 45-footer for birdie at the first. He drained a 20-footer at 14, and sank a 32-foot bomb to cap his round with a birdie at the last.
"For the most part the whole week has been pretty solid with the flat stick," Johnson said. "That was a gift on 18, but when you see putts go in, it just gives you a bit more freedom to be aggressive."
He was also pleased with the rest of his game.
"I'm in control of my golf ball," he said. "Off the tee was really good with the exception of maybe one tee shot, and I'm giving myself opportunities, a lot of looks."
Although it's been awhile since he made his way to the winner's circle, Johnson was looking forward to the chance to end his drought on Sunday.
"I feel like I know what I'm doing," he said. "I've been in this position before. I've excelled in this position.
Argentina's Emiliano Grillo was alone in fourth after a 65 highlighted by his eagle at the par-five 15th, where he reached the green in two and rolled in his 25-foot putt.
Villegas, meanwhile, headed a group on 12-under after an even-par 70.
Leading third-round scores on Saturday in the PGA Tour RSM Classic on the par-70 Seaside and par-72 Plantation courses at Sea Island, Georgia (USA unless noted):
195 - Robert Streb 65-63-67
198 - Zach Johnson 66-67-65, Bronson Burgoon 68-63-67
199 - Emiliano Grillo (ARG) 66-68-65
200 - Kevin Kisner 68-66-66, Kyle Stanley 67-65-68, Camilo Villegas (COL) 64-66-70
201 - Andrew Landry 68-68-65, Matthew NeSmith 72-63-66, Patton Kizzire 65-66-70
202 - Cameron Tringale 67-68-67, Keegan Bradley 67-68-67, Bernd Wiesberger (AUT) 66-68-68
203 - John Huh 69-68-66, Rory Sabbatini (SVK) 65-72-66, Matt Kuchar 70-66-67, Corey Conners (CAN) 67-70-66, Jason Day 69-67-67