Defending champion Karis Davidson shot back into contention at the Bowra & O'Dea Women's Classic with a four-under 70 to put pressure on the leaders heading into Wednesday's final round.
The Queenslander had started the third round 10 shots behind overnight leader Becky Kay, but reduced that deficit in half with the lowest round of the tournament so far this week at Lake Karrinyup.
Kay carded a 75 on Tuesday to see her advantage reduced to just a single stroke from South Australia's Ella Adams, who went round in 74.
Montana Strauss remained in third place after also shooting a level-par 74 with Davidson ominously perched just a shot behind at even-par for the tournament.
Davidson arrived in Perth already knowing that she - and Kay - could not be displaced from the top-two positions in the Karrie Webb Series, which has earned them $10,000 towards tournament and training expenses this year.
The Gold Coast duo will also get the rare chance to join 41-time LGPA winner Webb at the Women's US Open, which is to be staged at Trump National at New Jersey in July.
Davidson's quest to add to her Riversdale Cup and Dunes Medal wins during the series were jeopardised by a frustraing 36-hole opening day, when she shots rounds of 77 and 75.
And while she bogeyed the par-five second on Tuesday, Davidson returned to the form that secured her this title 12 months ago with a hat-trick of birdies on the front nine kick-starting her day.
Davidson carded seven birdies in all to catapult herself up the leaderboard and give herself a chance of catching Kay on the final day.
Kay started her third round with three successive birdies to move to nine-under and open a six-stroke lead over the field after closest rival Adams bogeyed the par-five third.
A triple-bogey eight at the seventh undid all Kay's good early work, however, and ensure the tournament remains up for grabs heading into the final round.
Kay's leaderhsip of the tournament and Davidson's low round on Tuesday ensured Queensland took a firm group over the race for the Interstate Team Event, with a 12-shot lead ahead of second-place Victoria duo Strauss and Stephanie Bunque.
Sharon Dawson remained on course to defend her Seniors 54-hole title after opening up a five-shot lead with a round to play.
Fellow Lake Karrinyup member Carman Palframan is Dawson's closest challenger with Melville Glades duo Leanna McVey and Shirley Van Der Brugghen two strokes further back.
Dawson stamped her authority over the event with a birdie at the par-four 18th to card a second-round 80.
Palframan leads the Mid Amateur event by three shots from Kojonup's Lisa Taylor with Peta Roberts a shot further back.