"I like to see the ball running and that's what this course offers me," said Yip, a regular on the Canadian Tour.
Asked if he though Scott knew who he was, Yip replied: "I guarantee he doesn't ...."
Rory McIlroy, trying to win for the first time this year, shot 69, seven behind Scott. McIlroy made the turn at 2-under, bogeyed 11 and 12 but had three birdies in his final seven holes, including on the 18th.
American Kevin Streelman, who played with Matt Kuchar on the runner-up American team in last week's World Cup at Royal Melbourne, shot 70 playing in the same group as Scott and Jason Day.
Day, who won the individual stroke play at the World Cup, also shot 70.
Scott could not recall starting any round with six birdies, thinking that he once had five in a row to start a round in Qatar. He finished his round Thursday with approach to nearly tap-in range on the ninth.
"I'm off to a good start, but a lot of work to do yet," Scott said. "It's been a long time since I shot a low round like this. It's a tough setup but it was a perfect morning for it."
Scott joked that since he started on the back nine with six birdies, then birdied his last four on the front nine, the scorecard will appear as if he had 10 consecutive birdies "maybe as time goes by, I can embellish and say I had 10 in a row."
Most of the best scores Thursday came in the morning groups as the wind picked up in the afternoon. Similar weather conditions are forecast for Friday when Scott will play in the afternoon.
"If the forecast stays the way it's supposed to I'll get the best of the conditions," McIlroy said of his scheduled morning tee time Friday.
"I'll try and go out there and shoot a good score and see what happens tomorrow afternoon for those guys. We'll get the best of the greens and hopefully I can hole a few."
Scott won the Australian PGA and Australian Masters before sharing the World Cup team trophy with Day last week at Royal Melbourne.
The previous golfers to have held the Royal Sydney record of 65 were all Australians: Chris Gaunt, Matt Goggin, Stephen Dartnall, Ewan Porter and Jason Norris.