England launched an impressive Ashes fightback on day two at North Sydney Oval, but a stubborn half-century from Ellyse Perry left the match precariously poised heading into the weekend.
Perry finished unbeaten, scoring 70 of Australia's 5-177, and looked untroubled as she faced 173 balls without offering a chance despite wickets stumbling around her.
A dogged final-session partnership with captain Rachael Haynes seemed to wrest the momentum back in Australia's favour, but that stand was broken at 73 with less than 20 minutes on the clock, moments after England took their second new ball.
"I always thought when they took that second new ball it was a danger period," Australian coach Matthew Mott said.
"They fired through those overs and got through, so it was pretty smart cricket from them; it was always going to be a challenge and it was a really good ball to get her [Haynes] out.
"We were certainly pretty happy to come off; I think we were counting down the balls at the end and hoping they didn't get the extra over in. It was proper Test cricket at the end there. They were coming in with a new ball firing in and it was dangerous.
"It was disappointing but I always thought it was going to be hard work those last 15 or 20 minutes. We got away a couple at the end which gave us a little bit of momentum at the end. All in all a pretty good last session after a bit of a battle for the rest of the day.???
Haynes was trapped LBW by speedster Katherine Brunt for 33 from 74 balls. Just a ball earlier she'd nicked one through first and second slip for four in front of 3613 fans at the famous suburban ground.
And she was perhaps lucky to survive an LBW shout half an hour before stumps off the bowling of impressive debutant Sophie Ecclestone before Brunt finally had her say.
Her partnership with Perry may yet prove a game saver for Australia, who were reeling at 3-61 midway through the second session in response to England's 280.
"She [Perry] invested a lot of balls in her innings at the start and she just started to find the gaps towards the end there and cashed in a little bit," Mott said.
"Mindful that she'll have to start up again in the morning against the new ball."
The visitors had the last laugh when they breached the 80-over mark 15 minutes from stumps and instantly opted for a new pink ball to work its magic under lights, as Australia had done successfully the night before albeit with a bit more time in the bank.
This was a crucial day for England, who had started the match strongly only to lose four final-session wickets on Thursday to hand Australia the upper hand.
Should Australia win the Test, they'll take an unassailable lead in the series and retain the Ashes. England must at the very least avoid defeat, but they'll have their sights firmly set on victory which would leave the Aussies needing to win two of the three T20 matches to hold onto the urn.
Australia needed an hour in the opening session to wrap up the England innings. Megan Schutt took a couple of scalps before Perry finished things off with 3-59 etched beside her name on the scoreboard.
Nicole Bolton (24) and Test debutant Beth Mooney (27) looked comfortable if not a little sluggish at the top of the order but both were undone in similar fashion, caught playing false shots to the on side.
The 18-year-old left-arm finger spinner Ecclestone was superb on debut, out-foxing Mooney before landing the prized scalp of veteran Alex Blackwell, who was trapped LBW for just six.
Perry's typical resistance followed firstly with Elyse Villani, whose rush of blood brought her unstuck when she was caught by Sarah Taylor off the bowling of Anya Shrubsole, and then with Haynes.