Australia have a mountain to climb to save the one-off Test at Wankhede Stadium after an unbroken 102-run stand between Deepti Sharma and Pooja Vastrakar lifted India to 7-376 at stumps on day two.
Sharma (70 not out) and Vastrakar (33no) came together just before tea in Mumbai on Friday on the back of a 4-14 collapse which had India 7-274 in reply to Australia's 219.
The strike-bowling pair showcased their batting abilities with career-best scores to render Australia wicketless in the final session, pushing India's lead to an imposing 157 runs.
Just before tea, Ash Gardner (4-100) single-handedly dragged Australia back into the contest, the first Test between these two teams on Indian soil since 1984 when a four-match series was drawn nil-all.
With India cruising at 3-260, Gardner's catch at deep square leg to dismiss well-set debutant Richa Ghosh (52) triggered a flurry of wickets.
Gardner then struck twice in as many overs with balls that kept low, trapping India captain Harmanpreet Kaur (0) and wicketkeeper Yastika Bhatia (one) lbw.
Then came the big scalp of the brilliant Jemimah Rodrigues (72), who speared Gardner to Annabel Sutherland in the covers to have India 7-274.
Australia threatened to roll the home side in the final session but they had no answers for Sharma's class and Vastrakar's heart, the duo leaving India well placed to notch their first-ever win over Australia in women's Tests.
Opener Smriti Mandhana top-scored with an attacking 74 before being run out before lunch.
On Thursday, new vice-captain Tahlia McGrath (50 off 56 balls), captain Alyssa Healy (38) and tail-ender Kim Garth (28no) were the only Australian batters to impress against a potent Indian attack led by seamer Vastrakar, who took a career-best 4-53.