The England skipper led an emphatic response to defeat against South Africa, blasting 108 from 66 balls to become the fourth batter to make a hundred at the event and send records tumbling.
Knight and Sharma put on a match-winning stand of 71 runs in just 39 balls as Western Storm chased down a target of 173 with one over to spare
Heading in the final T20I with an unassailable lead of 12-2 over England, Australia failed to chase down a target of 140, despite Ellyse Perry's valiant 60 not out off 50 balls.
England women trail Australia women 0-3 in the points-based, multi-format Ashes series.
Playing in a home World Cup final is a once-in-a-lifetime opportunity and these guys will know it, says Heather Knight.
England women defended a modest total of 119 by one run and inflicted a 3-0 whitewash on India in the third T2oI in Guwahati on Saturday.
India's spinners produced a fine show to restrict England women to 119 for 6 in the third T20I in Guwahati.
In the 1st and 2nd T20I, whether chasing or batting first, India managed less than 120 runs, which is below-par against a top team like England.
India handed Harleen Deol her T20 International debut in the first match against England, which the hosts lost by 41 runs.
Chasing 161, India women crumbled in their chase to finish on 119 for 6 to hand England women a 41-run win.