Shane Bertsch, who won the Charity Pro-Am at the Cliffs earlier this season and tied for second here last year, carded a 3-under-par 69. He shares third place with Scott Weatherly, Brendon De Jonge, Bill Lunde and Kyle Thompson.
Schultz opened with a two-putt birdie on the first at Fox Den Country Club. After seven straight pars, he ran home a 30-footer for birdie at the ninth.
The 32-year-old chipped to 3 feet for birdie at the 10th to get to 3 under.
Schultz stumbled to a bogey at the next, though. He got that stroke back with a birdie on 13 and closed with a 25-foot birdie putt at the last to share the lead.
'I'm very pleased,' said Schultz. 'It is tough out there. The greens are so firm, it's tough to get it close. You can't stop the ball on the greens.'
Schwarzrock played the back nine at 1 over after bogeys at 12 and 15 and a birdie on the 14th. He caught fire on the front side, though.
The 33-year-old kicked in a short birdie putt on one to get back to even par. Schwarzrock then drained consecutive 10-foot birdie putts from the third.
He made it three in a row as his 8-foot birdie try at the fifth fell into the cup. Schwarzrock then birdied the seventh before parring his final two holes.
'I just figured something out on the range that got me hitting it solid today,' said Schwarzrock, whose best tour finish is a tie for second at the 1998 Huntsville Open. 'I hit it really well today. I hit a bunch of good shots on my front nine, but just didn't capitalize.'
Robin Freeman, a playoff winner here in 1998, carded a 2-under-par 70. He was joined in a tie for eighth by Mathew Goggin, Tjaart van der Walt, Tom Carter, Jess Daley, Steven Alker, Troy Matteson and Fran Quinn.
Kim Felton, Jeff Freeman, Charley Hoffman, Zoran Zorkic, Dave Christensen, Chad Collins, Chris Couch, Kris Cox, Steve LeBrun, James H. McLean, David Morland IV, John Morse, Tim O'Neal, Wes Short and Esteban Toledo are one stroke further back at minus-1.