Postpublished at 18:55 British Summer Time 20 July 2017
And here's where it started going wrong for Australia as that century stand for the fourth wicket was ended with the dismissal of Elyse Villani.
Blackwell last out for 90
Aus captain Lanning dismissed without scoring
India's Kaur makes unbeaten 171 from 115 balls
Match reduced to 42 overs per side
India play England in Lord's final on Sunday
Amy Lofthouse and Mark Mitchener
And here's where it started going wrong for Australia as that century stand for the fourth wicket was ended with the dismissal of Elyse Villani.
Lydia Greenway
Ex-England batter on BBC Test Match Special
You can't help but think that was Australia's last chance of winning this match. Healy can go big, but she and Blackwell will have to do it for a long time.
Perry c Verma b Pandey 38 (Aus 140-5)
After 14 uninterrupted overs of spin, India turn back to the pace of Shikha Pandey - and it does the trick as an out-of-sorts Perry nicks one to the keeper, departing for 38 from 56 balls.
Dare we ask, have Australia's hopes departed with her? They need 142 runs from 95 balls.
Perry 38 from 55 balls, Blackwell 6 from 8
It was around this point in the Indian innings that Harmanpreet Kaur started moving up through the gears and left the Aussie fielders rushing for their tin hats. Australia will have to "go big" at some point but they're keeping their powder dry for now as off-spinner Sharma returns to the attack. Again, five singles from it. No fireworks.
Aussie captain Meg Lanning has a towel draped around her, sitting on the sidelines, talking to coach Matthew Mott. Will her side be heading home after today?
#bbccricket
Dave: I'm England through and through but I can't help but wonder if this is India's time for their first World Cup!
Yadav shelters her eyes from the sun as she readjusts the field. The required rate is now up above eight-and-a-half runs per over, but India can only milk the leg-spinner for five singles. Australia need 147 from 102 balls.
Lydia Greenway
Ex-England batter on BBC Test Match Special
You always know you're in a battle with Blackwell. She brings intensity. She can hit the ball to awkward areas, so it's quite hard to set a field.
Target 282 from 42 overs
The vastly experienced Alex Blackwell is the new batter, she's off the mark courtesy of a misfield from Mithali Raj. Perry and Blackwell help themselves to four singles, but what an important wicket for India.
Lydia Greenway
Ex-England batter on BBC Test Match Special
You can see what she was trying to do and it was a good option. But the ball wasn't quite there and she went through with the shot anyway. That's such a blow for Australia.
Villani c Mandhana b Gayakwad 75 (Aus 126-4)
Gone! Villani departs for 75 from 58 balls as she can't fully get hold of another attempted big hit and it's a straightforward catch for mid-on.
Here's a reverse-swept four from Villani;
Villani 75, Perry 30
Yadav is bowling from well behind the popping crease - barely in front of the stump line, in fact. She's barely bowling quickly enough for the ball to reach the other end without a following wind, so there's no pace on the ball at all - and her fifth over yields five singles.
Target 282 from 42 overs
Ellyse Perry has left most of the big hitting to Villani in this partnership, but for once she comes down the track and blasts Gayakwad wide of long-on for four. That's only her third four. Some low-risk singles mean these two have completed a century stand - with Villani scoring 72 from 53 balls and Perry 23 from 35 balls in that 100-run stand.
Target 282 from 42 overs
Perry punches Yadav for a single to the cover sweeper. Villani helps herself to a two, then reverse-sweeps a four through third man. Another single means it's eight from the over - exactly what they need to keep up with the rate. Yadav has 0-31 from four overs.
We're at the halfway point. At this stage, India were 77-2. Who's your rupee on?
This is Elyse Villani's highest ODI score - she's made just three half-centuries in her one-day career. Here she is reaching number three with a series of boundaries.
Target 282 from 42 overs
India continue to shuffle the three spinners - as Ebony Rainford-Brent alluded to on TMS, they may be ruing the fact they can't call on a fourth, Harmanpreet Kaur, who is off the field injured. Gayakwad has had a change of ends, and it seems to have done the trick for her as she spins down four dot balls to Perry before the tall all-rounder pulls a single to deep square leg. Villani chips one towards long-off, where Smriti Mandhana dives forward... but can't quite get there and it reaches her on the bounce as the Aussies run two. Mandana is limping for her trouble.
Perry 21, Villani 61
Two singles round off a good over for Australia - 11 from it. While all the talk was about Perry, Villani has utterly dominated this partnership.
We'll continue to bring you all the highlights of today's game - here's one of Villani's earlier fours through the covers.
Target 282 from 42 overs
Sharma back on, Perry is happy to play the supporting role as Villani - whose place in this XI had been questioned - swipes her 11th boundary past the keeper. An aerial sweep over square leg means Australia have reached three figures - and Villani has her highest ODI score.
Aus 92-3
Villani reaches her fifty from 41 balls with another powerful four wide of mid-off. Steely-eyed, she's already hit 10 fours.