'I played really well again today but I didn't make as many putts as I had earlier in the week,' said Delsing, who took the lead with a 66 in the first round before being joined atop the leaderboard by Joel Kribel in round two. 'This is a course where a lot of guys are making birdies so you just have to go out there and try to do the same.'
Delsing notched a trio of birdies on the front nine, the last with a two-putt from 15 feet after he drove the green at the 315-yard, par-four ninth. At the 563-yard 10th, Delsing chose to lay up with a seven-iron then holed his third shot with a lob wedge for eagle.
Although he three-putted for his only bogey of the day at 11, the 41-year-old St. Louis native recovered the lost stroke when a five-iron to five feet led to a birdie at the 18th.
In the only other time he had the third-round lead in his career, Delsing wound up closing with a 65 en route to a playoff victory over Jeff Freeman at last year's Fort Smith Classic.
Biershenk rolled in an 18-foot putt to save par on the final hole Saturday. He carded a 70 and was alone in second at 15-under.
Chip Beck, a four-time winner while on the PGA Tour, shot a 66 and has played his last 40 holes without making a bogey. He finished three shots off the pace with Kribel (70) at 14-under-par 202.
'Winning tomorrow for me would be like rising from the dead,' said Beck, whose last victory came 10 years ago at the PGA Tour stop in New Orleans. 'But it is just nice having the opportunity to win again. I can't tell you how fortunate I am to be here.'
Beck also finished runner-up in three majors: the 1986 and '89 U.S. Opens, and the 1993 Masters.
Barry Cheesman (69) was in fifth place at 13-under, one shot in front of Anthony Painter (65) and Mark Hensby (70). Andrew McLardy (70) finished alone in eighth at minus-11.
Gary Hallberg (66), Mike Heinen (66), Craig Lile (68), Lucas Glover (68), Chris Tidland (68) and Danny Briggs (70) were knotted in ninth place at 10- under-par 206.