England Women 146 for 4 (Taylor 77) beat Australia Women 131 for 5 (Cameron 35, Gunn 2-33) by 15 runs
Sarah Taylor put England on the brink of regaining the Women's Ashes with her best score in a T20 international.
Her 77 led England to a comfortable victory in the opening T20 to extend England's overall lead in the series to 8-4 with two rubbers to play. England can now do no worse than draw the series and Australia must win both of the remaining T20s to retain the Women's Ashes.
Taylor's 58-ball knock was made with clever placement and working the gaps well with the boundary difficult to find on a slow outfield. She struck six fours and was the mainstay of England's solid but not overwhelming total.
England began with a bang as six boundaries came from the opening 14 deliveries, despite losing Charlotte Edwards in the second over. Three overs later Heather Knight also fell to hasten two cheap overs to end the Powerplay during which England made 42. Then Taylor and Danielle Wyatt got together and ticked the innings along at just over seven-an-over in a stand of 88.
As it transpired, their 146 was comfortable enough as Australia never got the chase going. They lost both openers in the second over and made only 26 in the Powerplay. Jenny Gunn then removed Jodie Fields to stymie the recovery as the asking rate reached ten-per-over.
Gunn struck again in the 13th over, having Jess Cameron caught and bowled when well set but Ellyse Perry and Rachael Haynes took up the chase and struck five boundaries in 13 balls to make England sweat but the pair were left with too much to do.
Sarah Taylor said: "It's a great feeling to notch up another win, Danni Wyatt did a fantastic job, we knew if we stuck around and kept the score board ticking along we would post a good target. Anything can happen in T20 and credit has to go to our bowlers who defended the target well.
"We are two equally matched teams and we won't be taking anything for granted, yes we are playing good cricket but there are always areas we can improve on and we'll be looking at those ahead of Thursday, which will be a big game for us."