Louisiana Open winner Johnson Wagner fired a 7-under 64 to jump into a share of third place at minus-13. He was joined there by Jeff Klauk (66), Michael Long (67) and Jamie Broce (67). Seven more players are tied for seventh place at 12-under-par 201.
Armour, who is looking for his first Nationwide Tour win, opened with a bogey on the first. He atoned for that mistake with a two-putt birdie at the fourth. A birdie on the par-5 sixth moved Armour to minus-10.
The 30-year-old collected another birdie at No. 9. Armour parred the first seven holes of the back nine at Champions Run. He then drained a 13-foot eagle putt on the par-five 17th and birdied the par-4 closing hole to gain a share of the lead.
'I got off to a bad start, but regrouped with that birdie on No. 4, ' Armour admitted. 'I didn't drive it well on the back nine.'
Bowden was even par for his opening nine holes with two bogeys and two birdies. He started the second nine with a 6-foot eagle putt on the par-5 10th.
The two-time Nationwide Tour winner parred his next four holes. Down the stretch, he turned it on. Bowden birdied the par-4 15th from 18 feet out and made it two straight as he drained an improbable 80-foot putt at 16.
Bowden closed a run of three straight birdies on the 17th. That got him to 14 under as he closed with a par on the last to end alongside Armour.
'I've been playing good golf all year long, but I'm surprised to be in the picture. Realistically, I thought I had no shot after the first round,' Bowden said of his opening 70.
That 70 almost never happened either. His daughter got sick earlier in the week and he almost withdrew. Instead, he made the last-minute decision to come and it is paying dividends.
'I came into this week without any expectations at all,' admitted Bowden. 'After the first day, I thought it would be an absolute moral victory to just make the cut. I have no expectations tomorrow. I'll just go out, have fun and think about my daughter.'
Deane Pappas and Brad Adamonis each shot 66 to move into a share of seventh at 12-under-par 201. They were joined there by Brendon De Jonge (68), Andrew Johnson (68), John Mallinger (70), Bryce Molder (69) and Peter Tomasulo (67).
Second-round leader Bradley Hughes faltered to a 4-over 75 that dropped him all the way into a share of 35th.