ICC Women's World Twenty20, St Kitts:
Australia 104 (19.4 overs) tied with England 104 (17.3 overs)
Australia won on most sixes hit after Super Over finished tied on 6-2
England will look to bounce back against West Indies on Friday
Defending champions England lost their Women's World Twenty20 Group A opener against Australia on boundary countback after the match finished in a tie.
Sarah Taylor hit 46 from 44 balls but only two others reached double figures in their total of 104 from 17.3 overs.
Leah Poulton hit 23 for Australia but the scores were level when their last wicket fell with two balls left.
Both sides scored 6-2 in the "Super Over" but Australia won on countback because they hit the match's only six.
England head coach Mark Lane said: "We've had a few trial runs at the Super Over, so we were quite clear on how it was going to work, but unfortunately we were run out.
"We are disappointed, but we didn't lose the game on the Super Over, we lost it with the bat in the first innings."
Alex Blackwell, the Australian captain, said: "It was an extremely tense game but I was very proud of the way that we bowled and in the end I think we deserved our victory."
The return of England's star batter Claire Taylor after a winter break was a huge lift to the side but she was run out for a duck without facing a ball, only one ball after skipper Claire Edwards was dismissed for six.
Beth Morgan and Lydia Greenway were the only batters to provide support to Sarah Taylor as England lost their last four wickets in seven balls without adding to their total.
England reduced Australia to 63-7 but the Australian tail fought back to level the scores and looked set to snatch a dramatic victory in the final over.
However, Morgan ran out Rene Farrell to take the match to a Super Over.
After the scores remained tied, Australia were awarded victory on countback thanks to Jess Cameron's six off England's Holly Colvin earlier in the match.
Australia's Lisa Sthalekar was voted player of the match after taking 3-29 with her off-spin at Warner Park in St Kitts.
England play West Indies in their second match on Friday, and will come up against Deandra Dottin who on Thursday became the first woman cricketer to hit a century in Twenty20 cricket with a magnificent unbeaten 112.
She needed only 38 balls to reach the landmark in West Indies' 17-run win over South Africa in the first match of the women's tournament.
Dottin, batting at number six, hit nine sixes and five fours, with the second fifty coming off just 13 deliveries, and recorded the fastest century by either a man or a woman in ICC World Twenty20 cricket.
Dottin's sixth-wicket partnership of 118 with Shanel Daley is also the highest in any male or female Twenty20 match, beating the record of 77 set by Australia's Ricky Ponting and Michael Hussey in Auckland in 2005 and also equalled the second-highest partnership in women's Twenty20 cricket.
West Indies' total of 175-5 was also the highest total by any women's team in this format while South Africa's gallant chase, in which Shandre Fritz scored 58, was the second highest score by a side batting second in women's Twenty20 cricket.