Taking full advantage of the perfect morning scoring conditions, Davis ominously ripped through his opening nine holes in six under and picked up three more birdies coming home in a blazing start.
The magical round would have equalled John Senden's course record but wasn't recognised after officials opted for preferred lies following Wednesday night's heavy rain.
"I made a couple of nice putts to keep the score going. It was a really solid round," Davis said.
"I know this place relatively well and I have plenty of good memories in the bank to go out and play the course with, but that's by the far the cleanest round I have ever had around here."
The PGA Tour star has a one-stroke lead over American Patrick Rodgers, with West Australian Hayden Hopewell and Scotsman Connor Syme one shot further back at seven-under-par.
Min Woo Lee is right in the mix at the Aussie Open. PHOTO: Getty Images.
The three frontrunners all started at The Lakes, with Scot Grant Forrest recording the best morning round at The Australian, a six-under-par 65 to sit with three others in a tie for fifth.
The bookies pre-tournament favourite Min Woo Lee opened with a five-under 66 to be just four shots behind, while superstar Cameron Smith settled for a 70 in his first round since missing the cut at last week's Australian PGA Championship.
But the morning belonged to Davis.
Teeing off the 10th, the World No.43 collected four birdies and a brilliant eagle three at the short but treacherous par-5 14th to set the tone.
He made more birdies on the 4th, 7th and 8th holes but was furious at missing a short putt at the last that would have vaulted the 28-year-old to 10 under.
"Without the wind, it was awesome to make the most of the conditions the way they were," Davis said.
"I just felt like I had good clean control of my ball all day and give myself good putts for birdie."
The hot start comes six years after Davis won the 2017 Open at The Australian Golf Club next door, where he will play his final three rounds, assuming he makes the halfway cut on Friday.
Looking to complete the prestigious Australian PGA Championship and Open double, Lee reached the turn in three under but it was anything but smooth going.
He needed a chip-in to save par on the par-5 11th (his second hole of the day) after a wayward drive found the waste bunker, and duffing his devilish fourth shot into another trap from where he holed out to the roars of approval from the huge crowd following the marquee morning group.
Lee picked up his first birdie of the day on the 13th. He followed up with another on 14, added a third on 18 before saving par with a sumptuous sand shot to within a few centimetres.
Paired with Lee, Smith overcame some front-nine wobbles to stay in the tournament after his shocker at Royal Queensland.
The 2022 Open Champion hit two balls in the water – one right with his approach on the 11th and one left off the tee on the 14th – but scrambled for pars on both occasions.
But Smith couldn't get up and down from the bunker on the par-3 18th amid concerns the World No.20 and highest-ranked player in the 156-strong field could be headed for another premature departure.
Smith steadied though on his back nine to at least finish under par.
