Opener Beth Mooney's brisk half-century helped hosts Australia beat New Zealand by four runs on Monday to seal the last semi-final spot in the Women's Twenty20 World Cup and keep their title defence intact.
India, South Africa and England had already advanced to the knock-out stage with Monday's last Group A clash between the trans-Tasman rivals deciding the final contender for the trophy.
Both Australia, who have won four out of the previous five editions of the tournament, and New Zealand had lost their group outing against India and Monday's match at the Junction Oval was a virtual quarter-final.
New Zealand captain Sophie Devine surprisingly asked Australia to bat first and the hosts showed positive intent from the onset to stamp their authority on the clash, posting 155-5 from their 20 overs.
Leg-spinner Georgia Wareham then took the key wickets of Devine, who made 31, Suzie Bates and the dangerous Maddy Green in her 3-17 to derail New Zealand's chase and help Australia restrict them to 151-7.
Megan Schutt also picked up 3-28 with her medium pace as the total proved too steep for New Zealand to chase down, despite a valiant unbeaten 37 off 18 from Katey Martin.
Mooney, playing her 50th T20 international, anchored Australia's innings with a knock of 60 from 50 balls and got able support from the middle-order. She hit six fours and two sixes in her knock.
All-rounder Ellyse Perry, who overcame a hip injury to be fit for the match, and Rachael Haynes provided the late acceleration for the hosts. Perry hit 21 off 15 while Haynes scored 19 not out from eight balls.
Perry, however, hobbled off the field with a right hamstring injury during New Zealand's chase and did not return to the field.
Earlier, Sri Lanka off-spinner Shashikala Siriwardana marked her international swansong with figures of four for 16 to set up a nine-wicket consolation win for her side against Bangladesh.
Siriwardana received a guard of honour from both teams and had 14 dot balls in her spell despite bowling in the first six overs of the batting powerplay.
Bangladesh won the toss and opted to bat but struggled for momentum against Sri Lanka's disciplined bowling and posted a lowly 91-8 with Nigar Sultana Joty top-scoring with 39.
They dropped chances at the start of the Sri Lankan innings to end any hopes of a victory as their opponents added 51 for the opening stand between Hasini Perera and captain Chamari Athapaththu, who was out for 30.
Perera remained unbeaten on 39 not out to ensure Sri Lanka picked up their first win of the tournament.