Philip Pettitt, Jr. fired an 8-under-par 63 on Saturday and grabbed a 1-stroke lead entering the final round of the Boise Open.

Pettitt finished 54 holes at Hillcrest Country Club at 18-under-par 195, one shot ahead of overnight leader Russell Knox, who couldn't recapture the magic he displayed just a day earlier.

Knox shot 59 on Friday, becoming the fifth player in Web.com history, and the second in the past three weeks, to accomplish the feat. He followed that historic performance with a third-round 68 to drop into solo second.

"Everyone is bunched up now and tomorrow is going to be a shootout," said Knox. "I'm in perfect position. They're all going to find it difficult tomorrow to back up their good rounds."

Michael Connell fired a 61 and jumped into a share of third place at 16-under 197. He is joined there by Will Wilcox (62), who shot 59 two tournaments ago at the Utah Championship, Will MacKenzie (65), Chad Collins (67), Bronson La'Cassie (68) and Kevin Tway (63).

Jason Allred (67), Tim Wilkinson (64), Spencer Levin (66), Steve Wheatcroft (65), Jamie Lovemark (69), Danny Lee (65), Alex Prugh (67) and Nick Rousey (66) share ninth at minus-15.

Pettitt, who is seeking his first Web.com Tour win, opened the third round with three straight birdies, then added another at the par-4 sixth to turn in 32.

A birdie at the 10th preceded an eagle at the par-4 11th, which gave Pettitt a 1-stroke lead over Wilcox, Connell and Tway, who were in the clubhouse at 16- under.

Pettitt moved ahead by two with a birdie at the 12th before promptly giving that shot back at the next. He then parred two straight before again extending his advantage to a pair with a birdie at the 16th, then parred out to remain at 18-under.

"Numbers don't lie but sometimes they take a while to kick in," he said. "I've played significantly better the last few weeks. I knew it was a matter of time but there are only five weeks left (in the regular season) so I knew I needed to make a move somewhere along the line and I was hoping it was sooner rather than later."

Knox was consistent on Saturday, playing bogey free with a trio of birdies. It was a step back from his second-round brilliance, which featured eight birdies and two eagles, but the 2011 Chiquita Classic winner stayed within a stroke of Pettitt's lead by notching birdies on two of his final three third-round holes.

NOTES: Pettitt is making his 48th start on the Web.com Tour ... His best finish on the tour this season is a tie for 12th at the Chile Classic ... He ranks 83rd on the 2013 Web.com Tour money list ... Knox, Wilcox, Jason Gore, Doug Dunakey and Notah Begay III are the only players in Web.com Tour history to shoot 59.