'It was a shocker that the last putt went in,' said Felton, who earned $85,500 for his first tour win. 'I feel awesome. I haven't won anything this big before.'
David Peoples nearly forced a playoff, as he also posted a 69 to end at minus-10. Dan Olsen and Mathew Goggin shared third place at 9-under-par 279. Dave Christensen and Scott Gardiner were one stroke further back at minus-8.
Felton, who made the cut in seven of his 12 career Nationwide Tour starts prior to this tournament, opened with a birdie on the par-five first. He rolled in another birdie putt at three from 25 feet out.
The 30-year-old made it two straight with a tap-in birdie putt on four to get to minus-11. Felton, however, slipped back into a tie for the lead at minus-9 with back-to-back bogeys from the seventh.
Felton, who shared the lead entering the final round with Troy Matteson, steadied himself with a par at nine.
He got one stroke back with an up-and-down birdie on No. 10 at Fox Den Country Club. The Australian cruised to the 72nd hole with seven straight pars.
Peoples, playing one group ahead of Felton, birdied the last to close at minus-10. At the par-5 closing hole, Felton drained a 10-foot birdie putt of his own to seal his first-ever win on the Nationwide Tour.
'Obviously, the bogeys on seven and eight were disappointing, but I saw where I was still leading,' Felton said. 'I knew what I needed to do when David birdied the last hole. Somehow, I got that last putt in the hole.'
With the win, Felton vaults from 74th to 12th on the money list. The top-20 on the money list earn their cards for the PGA for next year.
'My first goal was to keep my card for next year,' said Felton, whose best previous finish was a tie for eighth earlier this year at the New Zealand PGA Championship. 'I've done that. Now my goal will be to finish in the top-20 on the money list.'
Peoples, who owns two PGA Tour titles, opened with a birdie on the first to get to minus-8. He parred his next six holes, then sank a 5-foot birdie putt on the eighth.
The 45-year-old faltered to a bogey on the par-4 12th. Peoples bounced right back with a birdie at the 13th. He nearly forced a playoff with his 10-foot birdie putt at the last, but Felton answered with a birdie on 18 to win it.
'It was a great day, despite coming up a little short,' Peoples said. 'Considering I started four-over on Thursday and wondering if I was going to play the last three rounds, 14 under over the last three rounds is pretty good.'
Wes Short and Nathan Green shared seventh place at 7-under-par 281. Deane Pappas, a two-time winner on the Nationwide Tour, finished alone in ninth place at minus-6.
Matteson struggled to a final-round 75. He slipped into a tie for 10th place at 5-under-par 283, where he was joined by Will Mackenzie, Rich Barcelo, Boo Weekley and second-round leader Shane Bertsch.