Perth - Rachael Haynes and Meg Lanning revived Australia's stuttering women's Twenty20 World Cup title defence with a match-turning 95-run partnership in the home side's tense five-wicket victory over Sri Lanka in Perth on Monday.

The four-time champions were on the brink of elimination at 10 for three chasing 123 before vice-captain Haynes made 60 and skipper Lanning managed 41 not out to rescue Australia, who lost their opener against India on Friday.

"Hopefully it settles our group down," player of the match Haynes told reporters.

"I hope today showed a little bit of our character."

Australia's victory inches them closer to Group A pacesetters India and New Zealand. Only the top two from each of the two five-team groups qualify for the knockout phase with India making the early running after beating Bangladesh by 18 runs in the later match.

Sri Lanka are all but eliminated having lost to New Zealand on Saturday.

"Our young side played really well against the world champions," said Sri Lanka captain Chamari Athapaththu, who top-scored with 50. "We lost the match but won hearts in the crowd."

Australia appeared in command after restricting Sri Lanka to a modest 122 for six from their 20 overs after Athapaththu elected to bat on a green-tinged WACA pitch.

But the match spectacularly flipped when left-arm quick Udeshika Prabodhani bowled opener Alyssa Healy for a duck and Ashleigh Gardner for two with pearlers. Australia crashed further after Beth Mooney was stumped for six off spinner Shashikala Siriwardene.

Lanning, playing in her 100th T20 international, had a lucky escape in the eighth over when she was caught behind on 15 only to be given not out in a decision unable to be overturned with Sri Lanka out of reviews.

Haynes, who was dropped twice, fell with 18 runs still needed but Lanning calmly guided Australia over the line with three balls to spare.

In the later match, India overcame a spirited effort from Bangladesh, who played their tournament opener.

After being sent in, 16-year-old sensation Shafali Verma whacked three sixes in her first seven deliveries to get India off to a flyer.

She then smashed her fourth six with a sublime chip down the ground much to the delight of the strong Indian contingent in the terraces. Her whirlwind 17-ball 39 ended when she holed out to a juggled catch by Shamima Sultana.

"She's been given free licence to play her game. She's playing fearless cricket," quick Shikha Pandey said of Verma.

India lost regular wickets, including two calamitous run-outs, but were powered by a late flurry from Veda Krishnamurthy (20 from 11) to reach 142-6.

Bangladesh fought hard but never seriously threatened in their chase finishing at 124-8. In-form Indian spinner Poonam Yadav continued her impressive form with three wickets.

Nigar Sultana, who top-scored with 35, believed Bangladesh could be competitive against Australia on Thursday in Canberra.

"We want to execute our plans and want to take all the positive things from this match into the next game," she said.