SAN JOSE, California, Oct 11, 2012 (AFP) - O'Hern, who will turn 41 next Thursday, had eight birdies in an 11-hole stretch and capped the bogey-free round on the CordeValle club course with a birdie on the par-five ninth hole.
"I just hit the ball lovely all day, was able to hit it close," O'Hern said. "I started off having to make a few par putts, crucial ones, sort of four- five-footers.
"Once I made those, it got me going. Then I made a few birdies on the front nine, which was my back nine."
O'Hern, of Perth, is winless on the USPGA Tour and has a three-stroke lead over European Ryder Cup star Nicolas Colsaerts, Jhonattan Vegas of Venezuela, and American Derek Ernst.
Charles Howell, John Mallinger, Jonas Blixt, Gary Woodland and Greg Owen all shot 66. British Open champion Ernie Els, of South Africa, opened with a 71 in the Fall Series event.
The Frys.com Open is one of four season-ending PGA Tour events aimed mainly at players trying to crack the top 125 on the tour money winners list to keep their playing rights for next year.
It was the lowest round of the year for O'Hern and it couldn't have come at a better time.
O'Hern came into the week 144th on the money list after just one top 10 finish in 23 starts this year. He has missed the cut in five of his past seven starts.
"I know I've got my work cut out as far as the money list goes," O'Hern said. "I know what I need to do. I need to play good golf. I've been doing that, I just haven't had the results unfortunately.
"Today is a perfect start to what I need to do."
He hit 14 of 18 greens in regulation and needed just 23 putts in the first round.
Colsaerts, of Belgium, is seeking to earn a PGA Tour card. As a special temporary member, he needs to finish the equivalent of 125th on the money list to earn a 2013 card. He is in 120th spot after earning $652,886 so far.
"I played pretty good," Colsaerts said. "I had a lot of very good shots early out.
"I got quickly under par. I was a little bit sloppy in the middle, but I just made sure I did my pars. I had a couple good up and downs and a couple good birdies to finish with."
Leading scores on Thursday after the first round of the $5 million Frys.com Open (par-71, USA unless noted):
62 - Nick O'Hern (AUS)
65 - Jhonattan Vegas (VEN), Nicolas Colsaerts (BEL), Derek Ernst
66 - Charles Howell, John Mallinger, Jonas Blixt (SWE), Gary Woodland, Greg Owen (GBR)
67 - Jeff Maggert, Garrett Willis, Patrick Cantlay, Rocco Mediate, Will Claxton, Vaughn Taylor, J.J. Killeen, Billy Horschel
68 - David Mathis, Jeff Overton, Bud Cauley, Jason Kokrak, D.A. Points