Sauers has overcome a rare skin condition called Stevens-Johnson syndrome. He was out of golf for five years before fighting his way back to playing shape.
"Overall, I'm happy the way I played," Sauers said. "I made one bad mistake on 17 and it cost me, but I'm still right there. I've got two days to go."
Brian Henninger, Mark Brooks, Hal Sutton, Michael Allen and Mark Bucek were two strokes back at 71.
Defending champion Fred Funk shot 75. Tom Kite had his first Champions Tour hole-in-one, acing the 194-yard 16th with a 7-iron, in a round of 76.
Bernhard Langer, a two-time winner this year, had a 77 — his highest score since the SAS Championship in October 2011.