Presnell missed a 6-foot birdie try on the 17th hole, then closed with a birdie on the Sandhurst course. He birdied 11 of the first 14 holes.
The Australian tied the tour record set by Paul Gow in the 2001 Canon Challenge at Castle Hill and matched by Ernie Els in the 2004 Heineken Classic at Royal Melbourne.
Presnell finished at 22-under 266. Australians Kurt Barnes and David Bransdon had 67s to tie for second.
"A few nerves crept in," Presnell said about his putt on 17. "But I'm stoked. I didn't do a great deal wrong. I drove the ball pretty good all week and my putter worked on Friday and particularly today."
"I thought I was completely out of it with absolutely no chance. But a few putts dropped in late on the back nine."
Presnell is preparing to play the U.S. Nationwide Tour.
"I head over on Thursday for a couple of events in South America, so this is a fantastic way to start the season," Presnell said.