Chip Beck, who took third place last week at the Omaha Classic for his highest finish in professional golf since a second at the 1996 Buick Open, is alone in second place at 5-under-par.
Sauers was nearly flawless Thursday, hitting all but two greens in regulation. He collected four birdies on his front nine and added two more at 11 and 14 to reach 6-under-par.
Sauers recorded his final birdie of the round at the 18th when he knocked a 5-iron to four feet.
'I've been hitting the ball really well for the last few weeks, but I just haven't been getting anything out of my rounds,' said Sauers, a two-time winner on the PGA Tour. 'It was fun today for a change.'
Sauers is one four players in the field that also competed at Kemper Lakes when it hosted the 1989 PGA Championship, which was won by Payne Stewart. Sauers did not recall much of the course from the '89 PGA Championship, where he tied for 58th.
'I usually remember every shot and every hole of the courses,' said Sauers, whose first-round 65 was his best round since a 64 in the second round of the 2000 Permian Basin Open. 'I just can't think that far back. I did remember about four holes or so, but other than that, nothing.'
Beck birdied two of his final three holes to take sole possession of second place.
'I guess it's good fortune and hard work. Bogey-free at Kemper Lakes is hard to do. It was a pretty sweet day,' said Beck, who only lives 15 minutes from the golf course. 'I feel like I'm still growing in my game. I've made some changes and I'm driving the ball better than I have anytime in my life.'
Dave Stockton Jr., Arron Oberholser and Jason Buha share third place at 4-under-par, followed by 12 golfers who are tied for sixth place at 3-under-par 69.
Full-field scores from the LaSalle Bank Open