'This feels so awesome, I don't even think I can describe the feeling,' said Miller. 'My first year as a pro was a real grind, and I hadn't put together four solid rounds since coming on tour. To get that first one under you belt is special.'
Erik Compton closed with a 3-under 68 to take second place at 13-under-par 271. Derek Gillespie and David Hearn shared third place at 11-under-par 273, with Jason Allred one stroke further back at minus-10.
Miller birdied the second and seventh to get to 11 under. He then ran off five straight pars around the turn.
The American birdied the par-4 13th. The 26-year-old Miller closed the tournament in style as he dropped in back-to-back birdies from the 17th to earn his first professional title.
'I began to get nervous on the 16th tee, but it should help my confidence knowing I can get over those nerves,' said Miller. 'When you have guys like Gillespie and Hearn coming from behind and posting a good number, it can get you thinking. Those guys can play. Winning a tournament of this caliber makes it all worthwhile.'
Compton nearly holed in for eagle on the 72nd hole, but his blast from a greenside bunker just missed going in. He settled for birdie and second place.
Mario Tiziani, Ben Ferguson, Robert Hamilton and Matt McQuillan shared sixth place at 9-under-par 275. Rob Labritz, Wes Martin and Brian Nosler ended one shot behind that group at minus-8.