Michael Putnam posted a 3-under 68 on Saturday to keep his 2-shot lead after three rounds of the Boise Open.
Putnam, who will go for his second tour title on Sunday, completed 54 holes at 18-under-par 195. After setting a new 36-hole record, Putnam also set the tournament's 54-hole scoring mark.
Rick Cramer set the old mark of 196 in 1996 and four others later matched his total.
Casey Wittenberg, the tour's leading money winner, carded a 7-under 64 to move into second place at minus-16. He was joined there by Scott Gardiner (64), Steve Wheatcroft (63), Tyrone Van Aswegen (67) and Luke Guthrie (62).
Jeff Gove, a 3-time winner on the Web.com Tour, managed a 4-under 67 in round three. He is alone in seventh place at 15-under-par 198 at Hillcrest Country Club.
Putnam poured in a long eagle putt on the second to jump to 17-under, where he was three clear of the field. However, he drove his ball out of bounds on the par-5 third and that led to a double-bogey.
That created a 3-way tie for the lead with Richard H. Lee and Van Aswegen. After a pair of pars, Putnam birdied the sixth to tie Guthrie atop the leaderboard.
"I've been in this position before, and I knew it wasn't going to be easy," said Putnam on TV of his up and down front nine. "I knew I wasn't going to make 17 more birdies or nine more birdies, like I did yesterday, but I knew it was going to be tough."
Putnam made the turn at minus-17 thanks to a birdie on the ninth. He was one clear of the field at that point, but dropped back into a tie for the lead after a bogey on No. 11.
The 29-year-old drained a 12-footer for birdie on the 14th to regain the lead. Putnam extended his cushion with a 2-putt birdie at the par-5 16th. His tee shot on 16 landed in a practice bunker and he got a free drop, then hit an 8- iron over trees and onto the green. He parred the final two to end there.
"I got two pretty lucky breaks. On 16 to have a shot, and then 18, I knew I had a backboard, but it ended up in a pretty good spot," Putnam said in a televised interview. "It was a tough day today, and I just kind of grinded it out."
Wittenberg, one of two 2-time winners this season, birdied three of four holes from the second. After eight straight pars, Wittenberg poured in four consecutive birdies from the 14th to grab a piece of second place.
Gardiner birdied three holes in a row from the second. Around the turn, he birdied back-to-back holes from the 11th and 15th to get to 16-under.
Wheatcroft had four birdies on both the front and back nines, while Van Aswegen mixed six birdies and two bogeys in his round of 67.
Guthrie, who turned pro earlier this year, had two birdies and an eagle in his first six holes. On the back nine, he ran off five birdies in a 6-hole span from the 10th. He parred the last three holes to post the fifth 62 of the week.
NOTES: Putnam could jump into the top 10 on the money list with a win on Sunday...Luke List, who trails Wittenberg by just over $3,000 on the money list, is tied for eighth at minus-13.