A superb 74 not out from Anneke Bosch fired South Africa into the Women's T20 World Cup final as they demolished defending champions Australia by eight wickets in Dubai on Thursday.

Set 135 to win, South Africa reached their target with 16 balls to spare, with Bosch, who struck eight fours and a six in her 48-ball innings, sharing a match-winning partnership of 96 with skipper Laura Wolvaardt (42).

In Sunday's final, which will be the first not to feature one of Australia or England, the South Africans will face either West Indies or New Zealand who meet in the second semi-final on Friday.

Australia, who have won six of the previous eight editions, had been the odds-on favourites to win a seventh title in the United Arab Emirates.

However, they had no answer to the South Africans for whom this marked a measure of revenge for defeat by Australia in last year's final in Cape Town.

Put into bat, Australia struggled from the start with the normally fluent Beth Mooney top-scoring with a grafting 44 that included just two fours.