A career-best score from Ashleigh Gardner powered Australia to 5-173, but India's top order came out in scintillating fashion to secure a thrilling victory on Saturday with three balls to spare.

India still needed eight runs off the last seven balls despite being in command for most of their innings.

But two boundaries took them home in the third-highest successful chase in WT20I history.

Australia will have to defeat England, who they lost to earlier in the tournament, on Sunday to be assured of their place in Wednesday's decider.

Indian opener Shafali Verma came out swinging, with her 49 from 28 balls setting the visitors en route to their second win of the series.

Smriti Mandhana (55) and Jemimah Rodrigues (30) also played vital steering knocks, with the hosts' sloppy performance in the field not helping their cause.

Earlier, player of the match Gardner's sparkling 93 from 57 balls easily eclipsed past her previous best of 63 not out.

She was caught at mid-off going for one big shot too many with her maiden ton in sight.

It was Gardner's third half-century in her 32nd T20 international.

After coming in at No.3, Gardner's knock was not without its challenges, as she was almost stumped and came close to being caught a number of times.

"It's bittersweet to have a personal innings like that but I always try and bat for the team and try to make as many runs for the team," Gardner said.

"(India) clearly had a game plan that they were always going to go hard in the first six ... for them, it came off today."

But her supreme innings allowed Australia to recover from a disastrous start when Alyssa Healy was dismissed for a third-ball duck.

It continued Healy's poor run of form in the tri-series, which is a concern leading up the T20 World Cup in Australia.

Captain Meg Lanning impressed with a cameo of 37 from 20 balls.

Australian Associated Press