He finished at 19-under-par 265 and won by a single stroke over Alan McLean, who fired a 65 and took second place for the second time in as many weeks.
'It hasn't really sunk in yet, but it feels pretty good right now,' said Risdon. 'I've had a few chances but you really need to play well on the weekend out here. I was able to do that.'
Kevin Kim finished alone in third place at minus-16 after a final-round, 5-under 66.
Risdon's lead was three shots after eight holes, but a bogey at the ninth and a McLean birdie at No. 10 cut the margin to one.
Risdon actually surrendered the lead to McLean, but flew by him at the 15th. He drove into the trees at the par-5 hole and laid up with his second. Risdon hit a sensational wedge that bounced a few times before falling in for an eagle.
Risdon was not even aware that gave him the lead.
'I honestly thought I was up by three after making that,' admitted Risdon. 'Obviously, that was clutch. I went to the next tee and thought to myself, 'Let's try to make three pars coming in and see if it holds'.'
He parred out for the win.
Michael Harris (67), Joseph Lanza (68) and the tour's leading money winner Spencer Levin (66) tied for fourth place at 14-under-par 270.
Josh Geary (69), Mike Grob (69), Scott Hawley (67) and Marc Lawless (63) shared seventh place at minus-13.