Leg-spinner Poonam Yadav bamboozled Australia as India opened the seventh edition of the Women's Twenty20 World Cup with a stunning upset of the reigning champions and tournament hosts by 17 runs at Sydney Showground on Friday.
Australia restricted India to 132 for four and looked on course to run down their victory target when a half century from Alyssa Healy got them nearly halfway there.
But Yadav (4-19) removed the opener right after she reached the milestone and then, roared on by a crowd of 13,432 overwhelmingly backing the visitors, wreaked havoc with a string of "wrong'un" deliveries that the Australians were unable to pick.
Rachael Haynes and Ellyse Perry were sent back in successive deliveries and Yadav was only denied a hat-trick when wicketkeeper Taniya Bhatia was unable to take a difficult chance off the bat of Jess Jonassen.
Bhatia made no mistake off yet another Yadav "wrong'un" to remove Jonassen cheaply two overs later and Australia were reeling at 82-6.
The four-times World Cup winners were unable to recover despite a dogged 34 from Ash Gardner, the righthander avoiding becoming Yadav's fifth victim only after the umpires ruled the Indian's looping delivery had bounced twice.
Seamer Shikha Pandey (3-13) dismissed Gardner caught and bowled in the final over and Molly Strano was run out on the penultimate ball to end the innings on 110 all out.
"It's a great feeling, I'm really happy for our girls," said India captain Harmanpreet Kaur.
"We were just looking for 140 and then let our bowlers win the game and that's what happened. Our team is looking very nice and if we do well in this tournament we will definitely win this World Cup."
Australia had started the night by winning the toss but made a nervous start and their Group A rivals took full advantage, racing to 40 without loss in the first five overs.
Teenager Shafali Verma was the main driving force and the 16-year-old opener smashed five fours, including one sublime cover drive, and a booming six in a 15-ball 29.
Smriti Mandhana also started brightly but had only 10 runs on the board when she was trapped lbw by Jonassen and the onslaught stalled when the left-arm spinner dismissed Verma and skipper Kaur was stumped for two.
Deepti Sharma (49 not out) and Jemimah Rodrigues (26) put on 53 for the fourth wicket but India never regained the early momentum and Australia would have been confident of reaching their target and taking charge of the group.
"We didn't quite execute with the bat unfortunately," said captain Meg Lanning.
"India bowled really well tonight and thoroughly deserved their victory. It's not ideal, but if we win our remaining games in the pool we'll still go through."
The top two teams in each of the two groups go through to the semi-finals on March 5, three days before the final at the Melbourne Cricket Ground.