Ellyse Perry registered the highest Test score by an Australian to leave England battling to save the one-off day-night Test and keep their Women's Ashes hopes alive.
All-rounder Perry had never previously reached three figures in any form of international cricket but a masterful innings of 213 not out propelled Australia to 448-9 declared at the North Sydney Oval.
The tourists need to avoid defeat to keep the multi-format series alive and openers Lauren Winfield and Tammy Beaumont at least survived a testing spell under lights to usher their side to 40-0 at the close - still 128 runs in arrears.
If England do succumb to defeat on the final day, it will be in large part due to Perry, who took 3-59 before engineering Australia's recovery from 168-5 over the course of the previous two days.
There were century stands, too, with Alyssa Healy, who contributed 45, and Tahlia McGrath, dropped on 0 before going on to make 47, but England found Perry immovable in a 374-ball stay that included 26 fours and one six.
Hers was the key wicket when she resumed on 70 and, despite England's persistence, there were precious few chances of note, with Perry bringing up her maiden hundred for Australia by tickling Laura Marsh's leg-side delivery fine for her 17th four.
With the Southern Stars closing in on England's first-innings 280 all out, Marsh finally made the first breakthrough of the day as Healy clubbed to Anya Shrubsole at mid-on.
Test debutant McGrath was shelled at extra cover in the next over by England captain Heather Knight, and it proved a costly drop with the batters establishing a healthy lead for Australia.
Perry breezed past her 150 and looked utterly unflustered as England started to tire in the field although McGrath was denied a fifty on debut after miscuing a Georgia Elwiss full toss straight to Nat Sciver at mid-on.
There was a cameo 24 from Jess Jonassen but when she and then Amanda Wellington departed in quick succession, there were fears Perry would be left stranded as she closed in on a double ton.
On 194, she celebrated reaching the landmark after lofting Marsh to deep midwicket only for replays to show the ball had landed a couple of feet inside the boundary rope.
She showed her resolve, however, by quickly refocusing and a lovely drive down the ground off Sophie Ecclestone in the next over saw her to a double hundred, this time to more muted celebrations.
She then hammered a four then a six off Ecclestone to overhaul Karen Rolton's previous Australian Test-best 209 not out and go third on the all-time list, behind Pakistan's Kiran Baluch and India's Mithali Raj.
Australia promptly declared with a 168-run first-innings lead in an effort to make inroads into England's batting.
There were a couple of nervy moments for England but Winfield and Beaumont made it to the close.