A hip injury to superstar Ellyse Perry has soured Australia's dominant first day of the historic women's Ashes Test at the MCG.
Captain Alyssa Healy's decision to bowl first after winning the toss paid off, with Alana King's spin masterclass skittling England for 170 in front of 11,643 fans on Thursday.
In reply, Australia batted for 22 overs before stumps, making it to 1-56 in the day-night Test.
But Australia will be sweating on the fitness of Perry, who didn't return to the field after leaving to be assessed during the second session.
The 34-year-old landed awkwardly on her hip while diving in the field, with hope the injury is just soreness instead of anything more sinister.
Due to come in at No.3, Perry was replaced by Annabel Sutherland, who smashed 210 in Australia's last Test in February.
Sutherland (24no) will resume batting on Friday with opener Phoebe Litchfield (20no).
Debutant Georgia Voll was the only Australian batter to be dismissed, slashing at a wide delivery to be caught behind off Lauren Bell's bowling.
Voll, presented with her first baggy green by the legendary Belinda Clark, was fuming at herself for falling in such disappointing fashion.
In the first women's Test at the MCG since 1949, it was two 21-year-olds who were given the honour of opening the batting for Australia.
King was the star of the day, bamboozling England with 4-45 - her best Test figures.
With the Shane Warne Stand behind her, King bowled 23 overs unchanged to destroy England's middle order, even taking the prized scalp of Nat Sciver-Brunt (51).
"Loved playing at the MCG ... it's home for me, and to bowl the whole session was pretty cool," King said.
"It can't get much better than that.
"(Captain Healy) tried to get the ball out of my hand at stages, but I'm like 'Midge, I'm in a really good rhythm'."
England's innings ended 50 minutes into the final session following a clumsy run-out.
Pink-ball Tests have traditionally been the domain of fast bowlers in men's cricket, but King proved spin has a vital place, too.
Earlier, Kim Garth skittled England's top order by striking in the first over, dismissing Maia Bouchier (2) thanks to a stunning catch by wicketkeeper Beth Mooney.
The Irish-born star later claimed the crucial wicket of England captain Heather Knight (25), who looked set to deliver on her promise of playing her best when she has a point to prove.
Knight was trapped lbw, not even bothering to use a review as she walked off to leave Sciver-Brunt to bat with Sophia Dunkley.
Quick Darcie Brown (2-47) took the other wicket of the first session, removing opener Tammy Beaumont (8).
England are trying to avoid an embarrassing 16-0 whitewash after losing the three ODIs and three Twenty20s.
Under a cloud after missing the T20s with a foot injury, Healy was trusted by selectors to make it through the four-day Test.
Healy isn't taking the gloves in this match, with Mooney to continue wicketkeeping after handling it well during the T20s.