Four golfers were tied for second with 67s, including Robert Allenby, who is trying to win his third successive tournament in Australia. Allenby, who won the Australian Open and PGA, was joined at 5-under by fellow Australians John Senden, Adam Bland and Steven Conran.
Peter OMalley of Australia and Bradley Iles of New Zealand were another shot back at 68. American Bubba Watson was tied for 13th after a 70 while Stuart Appleby had an even-par 72, defending champion Richard Green 73 and Adam Scott 76.
OHern is trying to win his first tournament since 1999. He has had 23 top 10 finishes in 51 tournaments in the past two years, and finished third in the HSBC tournament in China three weeks ago, second in the Australian Open two weeks ago and third in last weeks Australian PGA.
The last couple of weeks Ive just struck the ball beautifully and played really well, said OHern. I just havent made the putts.
But today I didnt hit the ball as well as I have been and all of a sudden you shoot eight-under. So its amazing what happens when you get the putter going.
OHern, who started on the 10th hole, eagled the 14th. He added his second eagle'with some good fortune'on the par-5 seventh.
I was lucky to be left-handed (on the seventh), said OHern. I was on the edge of the bunker and if I was right-handed I wouldnt have been able to go for it. So it was just one of those days when you get a break like that.
Allenby had an eagle to start his round and mastered an unpredictable breeze swirling around Huntingdale. He birdied two of his last three holes.
I think that showed today that Ive still got the swing, I am still making putts, it is all there, Allenby said.