The world number two burst out of the blocks with six straight birdies but lost his rhythm midway through his round and had to settle for eight straight pars.
He bounced back with a superb tee shot on the par-three sixth and sunk the short putt to spark another run of four straight birdies and smash the previous course record by three shots.
"I can't sit here and complain about anything but a bit like last week in the first round, the swing wanders on a couple of shots and it did it again today," Scott said.
"It's not quite in the slot, although I hit a lot of great shots today.
"It's a bit – I don't know the right way to say it – it's not as free flowing as the first couple of weeks (at the Australian PGA Championship and Australian Masters).
"The swing is a bit of hard work for me at the moment. I can still hit good shots obviously but hitting a few average ones as well and I got away with the bad ones with some good saves."
"I felt like there's been a good round in me for four weeks and finally I threw it out there today."
Scott, who is looking to become the second man to win Australia's Triple Crown in a single season, leads little-known Canadian Ryan Yip (65) by three shots heading into Round 2.
The 33-year-old is renowned as a strong front runner but concedes matching his opening round performance will take some doing with wet and windy conditions forecast for Friday.
"It's a mindset, you want to be a good front runner, you want to be out there and when you're playing well you want to keep your foot on the gas," he said.
"I've had a few times in my career where I ran away and won by several shots. It's a good attribute to have, it's hard to do but it's a good attribute if you can do it.
"Tomorrow's a whole different ballgame and backing up a low round is something that's hard to do and you don't often see guys go back to back low like that.
"So I'm going to have to come out tomorrow and try and get control of my game and mind again and just deal with the conditions as best I can."
Meanwhile, the reigning US Masters champion admits he was blown away by the size of the gallery that was on hand to watch him tear up the tricky Royal Sydney layout on Thursday morning.
"I couldn't believe how many people were there this morning early and the crowd swelled really quickly in the first couple of holes, it was fantastic," he said.
"To come home and see how enthusiastic everyone is about coming out and watching.
"I wasn't expecting that this morning at all, maybe tomorrow afternoon but just incredible crowds this morning and so it was nice that I was able to hit a few nice shots for them and get it going."