Australia's Kirsten Rudgeley, Kelsey Bennett and Stephanie Bunque are out-performing star compatriots to be perfectly poised at the $1.7 million tournament at Adelaide's Kooyonga Golf Club.
Rudgeley (five under) fired a stellar five-under 67 in Friday's second round.
The West Australian shares the lead with Bennett, Wales' Darcey Harry and Germany's Alexandra Forsterling - the latter trio are on the back nine of their second rounds.
World No.620 Bunque (four under) carded a four-under 68 and is level with Sweden's Moa Falke and France's Agathe Lainse, who are also yet to compete their second rounds.
Big-name Australians Hannah Green (one under) and Minjee Lee (even par) are midway through their second rounds, while compatriot and fellow major winner Grace Kim signed for an even-par round and remains three over.
The star trio had been billed as the main hopes of breaking Australia's 12-year drought of an open winner - the last local to salute was Karrie Webb in 2014.
But Rudgeley, Bunque and Bennett are staking claims to become just the fourth Australian to win their national open, joining five-time champion Webb, Jan Crafter and Jane Stephenson.
"It's cool to be able to almost do your thing on the sidelines," Bunque said.
"To be able to just put together a good couple of scores for the first two days, I'm building on my confidence.
"I know that I am a good player and I know that I am capable of putting on a good show."
Bunque, a 28-year-old from Melbourne, revelled in a hot streak featuring five birdies in eight holes.
And Rudgeley, a 25-year-old who was born in London and moved with her parents to Perth aged four, drained five birdies in a seven-hole stretch.
"It was a steady round of golf," said the world No.132.
"I putted well and struck the ball nicely. And when I made a mistake, I made up for it ... it was definitely nice."
19°C