In front of a record crowd of 13,432 for a stand-alone women's match, the hosts lost 4-15 midway at the Sydney Showground through their innings to slump to the shock defeat on Friday.

Australia were cruising at 2-67 in pursuit of 133 after an Alyssa Healy half-century, before legspinner Poonam Yadav ran through the hosts with 4-19 before they crumbled to be all out for 115.

The loss leaves the tournament favourites in a potentially perilous position.

After being asked about the final on March 8 for the past two years, they now likely need wins over Sri Lanka, Bangladesh and a very dangerous New Zealand.

They may also still need to rely on net run-rate to qualify for the semi-finals if they win all three of those, depending on other results.

"We love a bit of pressure, that's fine," Healy said.

"One of the blessings of our really crazy schedule is we don't have a lot of time to dwell on it."

The night had earlier looked so bright for Australia.

After 16-year-old Shafali Verma (29 off 15) got India off to a flyer at 0-40 after four overs, Jess Jonassen took 2-24 to strangle the visitors in the middle overs.

Ellyse Perry also took 1-15 - including the key wicket of Verma - from three overs, while Delissa Kimmince had 1-24 from four.

Healy then answered her critics with a thumping 51 from 35 balls, as she regularly went aerial down the ground with confidence.

After scoring only 24 runs in her last six innings, Healy finally resembled the superstar that was player of the tournament in Australia's 2018 success.

She hit six fours, and brought up her half-century when she hit Yadav back down the ground for six.

But when she bunted her next delivery back to be caught-and-bowled, the match swung.

Yadav removed Rachael Haynes and Ellyse Perry in successive balls the next over with wrong'uns as they advanced down the wicket.

The first completely deceived Haynes to have her stumped for six, before Perry went first ball when she was bowled between bat and pad.

The Indian spinner bowls at just 60km/h, but completely deceived Australia after not bowling to them in the recent tri-series through a finger injury.

"Upon reviewing it later, there will be some comments about how we approached that," Healy said.

"We planned for her, we just didn't play her as well as we should have.

"Me getting out wasn't ideal, you probably needed a match-winning score there.

"At one stage we needed a run a ball, and to let it push out to eight or nine an over isn't ideal."

Ashleigh Gardner then put up a lone-hand late fight, as the only other Australian to reach double figures with 34 before succumbing in the final over in a forlorn bid to find the boundary.

Australian Associated Press