It was the quintessential Australian performance. They had no need for a win in their fifth and last group game, having already qualified for a Women’s T20 World Cup semi-final by winning their first four. India, conversely, desperately needed one to qualify. And it looked as if they had it, after a late surge with the bat to reach 170, then an early squeeze to have Australia needing 86 from eight overs.

Then in a trice it was gone, as an accelerating century stand from Ellyse Perry and Ash Gardner squashed the world-record chase with an over and six wickets to spare. Ruthless, nerveless, pitiless.

Australia’s stroll to the semis also ushered through a far less confident, less assured South Africa, who had earlier in the day on the same Lord’s pitch crept past a modest Bangladesh total of 117 in more deliveries than it took Australia to make 172. South Africa’s nerves from the end of their chase lasted through most of the next match, with most players staying at the ground to see in person whether they would reach the knockouts, as they did with four wins ahead of India’s three.

For Australia, the match was a risk-free chance to experiment. Lucy Hamilton and Kim Garth formed a double seam opening attack, with the leg-spinner Alana King left out, even though Australia has relied on slower bowling through much of the tournament. Perry, whose bowling in recent years has become a rarity, got an over in the powerplay. So did Gardner. Sophie Molineux didn’t, despite doing the job through the tournament to date, instead trying her left-arm spin in the 20th over, when it was savaged by her rival captain, Harmanpreet Kaur.

Despite the changes, Australia were well on top until that late flourish. India’s star opening pair, Smriti Mandhana and Shafali Verma, were kept in check despite occasional big hits, adding 66 together but taking almost half the innings to do it.

Frustrated, Verma tried an ungainly heave to lose her stumps to Molineux, while Mandhana glimpsed a phantom run that evaporated as she approached it. Jemimah Rodrigues was busy but kept finding the boundary riders.

It was only in the last two overs that things really lifted for India, with three sixes from Harmanpreet and one from Rodrigues, though two of those scoring shots were dropped over the rope when catch attempts from Georgia Wareham and Phoebe Litchfield went awry. Australia will want to tidy that up, but perhaps didn’t mind having the extra runs to chase as a way to test themselves out at a gallop rather than a canter.

Litchfield didn’t find that rhythm on return from three matches out with a quad injury, swinging hard but only making clean contact when she belted her own thigh pad in frustration. Her 24 from 25 followed Georgia Voll’s dismissal second ball of the innings, having drilled the first through cover for four, then gone lbw after Renuka Singh Thakur correctly asked for a review.

When Beth Mooney holed out to long on for 22, the score was 68 for three, Australia needing a further 103 runs from 65 balls, and with so many players having struggled for timing on the Lord’s surface, that was a steep ask.

But while the required run rate climbed for three more overs, Perry and Gardner got settled and flipped it, taking 17 runs from a Radha Yadav over, 16 from Sree Charani, 12 from Shafali Verma, then, as Harmanpreet reverted from spin to seam, another 17 from Renuka.

Perry repeatedly threaded the gaps at cover and point despite populated fields, Gardner clobbered two sixes on the pull and another down the ground, and with three overs to go the target was under a run a ball. India’s faces showed a team that was already beaten.

Had they needed to, the Australians could have finished the game with two overs to spare. Instead, both raised fifties, Perry gave up a catch on 56, and Wareham ended things with a straight four.

Beyond the ramifications for India and South Africa on the day, the nature of the result sends a warning to all of the other three semi-final teams. Australia had nothing to gain, were happy to experiment, and still ran down a good team like a freight train. It will take something special to derail them from here.