Tidland, one of three overnight co-leaders, finished 54 holes at 13-under 197 and is two clear at Hardscrabble Country Club.
'It was there to get today,' said Tidland. 'Fortunately for me, no one else got it deep today. Two-under out here is a fine score. It doesn't kill me, but there are a lot of people with a chance.'
Gavin Coles, the second co-leader from Friday, posted an even-par 70 and is tied for second place with first-round leader Phil Tataurangi (66) and Justin Bolli (65), The group came in at 11-under 199.
Tidland watched others move ahead very early on, but first broke into red figures with a birdie at the par-5 third hole.
Tidland's birdie at three took him one clear, but Tataurangi flew out of the gate. He birdied one, two, three, five, six and seven to assume the top spot on the leaderboard. When Tidland bogeyed the fifth, he fell two back, but when he birdied six, he got within one of first.
Tataurangi bogeyed the par-4 ninth to fall into a tie for the lead with Tidland. That didn't stay that way for long. Tidland birdied the par-4 10th to go one ahead at minus-13.
From that point, Tidland just played steady golf and let his chasers fall.
Tataurangi bogeyed 13 and 14, but got one back with a birdie at the last.
Bolli didn't threaten the top of the leaderboard until birdies at 16 and 18 and that only got him within two.
Coles also recorded two late birdies, but didn't get him close enough thanks to a pair of bogeys late in his front nine.
Tidland cruised into the clubhouse with eight consecutive pars to take the third-round lead. If he were to hold on Sunday, it would be his second Nationwide Tour win after last year's Boise Open, and would all but assure him his PGA Tour card for next year.
'The course is pretty tough if you don't hit fairways,' said Tidland. 'It's getting firmer and it's forcing you to change your lines a little bit. I'd much rather be in the lead because they've got stuff to make up, they've got to shoot lower than I do (tomorrow) to catch me.'
Jason Enloe, the last of the second-round co-leaders, struggled to a 1-over 71 on Saturday and fell into a tie for fifth place with Andrew Buckle (65), Brian Smock (66) and Dustin Risdon (67). The group came in at 10-under-par 200.
Wil Collins shot a four-under 66 and is alone in ninth at minus-8, while Alex Prugh (68), Josh Broadaway (68) and Kris Blanks (71) share 10th at 7-under 203.