David Frost fired a 6-under 66 in the third round Saturday and took a 1-shot lead at the Regions Tradition.
Frost, who teamed with Michael Allen to win the Liberty Mutual Legends of Golf last year, finished 54 holes at 12-under-par 204.
Fred Couples, who finished fourth last year, used a 4-under 68 to move into second place at minus-11.
Second-round leader Duffy Waldorf managed a 1-under 71 in round three. He dipped into a share of third with 2010 runner-up Allen (69) and Morris Hatalsky (67) at 10-under-par 206.
Scott Hoch (69), Loren Roberts (70), Jeff Sluman (72), Esteban Toledo (69) and Bart Bryant (70) are tied for sixth place at minus-8 at Shoal Creek Club.
Two-time defending champion Tom Lehman shot 3-under 69 on Saturday and finished alongside five others at 7-under 209.
Frost broke through a crowded leaderboard late in the round to grab the lead with one round to go. He opened with back-to-back birdies at five and six. Frost tripped to a bogey on the seventh, but came right back with a birdie at the eighth as he headed to the turn at minus-8.
On the back nine, Frost birdied the par-5 11th and came back with a birdie at 13. At that point, he was part of a 4-way tie for the lead.
Couples was also in that group. He opened with a birdie on the first, then parred his next eight holes. Couples converted birdie chances at 10 and 12 to join Frost, Allen and Hatalsky atop the leaderboard.
At the 15th, Couples dropped in a birdie effort to move one clear at minus-11. However, he would end there as he parred the final three holes.
"It was a good day. I played the par-5s at even-par, which is unusual for me, but I played them very poorly. I actually made some good up-and-downs to save par," Couples explained. "Then the other 14 holes I played really well. I wasn't in too much trouble basically because when I drove it in the rough, I judged my second shots pretty well out of the rough today, which certainly helps."
Frost parred Nos. 14 and 15 before sinking a birdie try at 16. That moved him alongside Couples at 11-under. Frost made it two in a row as he also birdied the 17th to grab the outright lead.
"I made a lot of good shots out there today. I made one unfortunate bogey, but it's a tough golf course, so I'm not too disappointed with that round," Frost stated. "I think the mud really comes out more in the afternoon than the morning. It's still wet so it skids and then it dries out in the afternoon, so we might have had it a little worse than the morning guys. But hey, it's golf, you know? It's a game and we've just got to play by the rules."
NOTES: With the threat of inclement weather on Sunday, officials moved up tee times to 8:30 a.m.-10:30 a.m. (ET) ... Corey Pavin had a hole-in-one on the par-3 eighth ... Frost will go for his fifth Champions Tour title and first major championship victory on Sunday.