Aussies Cement T20 World Cup Final Spot After Thrilling Win Over South Africa

Australia beat South Africa by a rain-affected five runs in a dramatic women's Twenty20 World Cup semi-final, setting up a date with India in the decider.

In a dramatic Thursday night at the SCG, Australia's 5-134 became a target of 98 from 13 overs for South Africa, before they held them to 5-92 in a thrilling finish.

But Australia's title defence could have been over so much earlier, with rain threatening to wash them out and send the Proteas through to the final.

After England's tournament had been ended without a ball bowled in their semi-final against India, Australia' semi-final was delayed by 25 minutes.

The match was then held up for another 38 minutes between innings, before players returned to the field nine minutes before play was set to be called off.

"I'm pretty relieved," captain Meg Lanning admitted.

The Australian women's cricket team celebrate their win over South Africa. Image: AAP

"Just excited for the opportunity that is coming up. It wasn't an easy day.

"We had a lot of waiting around and just hoping the weather was going to hold off."

Light rain then fell for the majority of the second innings, as Megan Schutt helped the hosts strangle South Africa out of the game in the chase.

She was clinical, sending down three overs for 2-17 and removing the dangerous Proteas captain Dane van Niekerk with a brilliant inswinger.

Delissa Kimmince also sent down 1-16 from three, as Jess Jonassen defended the 19 required from the final over despite late hitting from Laura Wolvaardt (41no from 27).

"I would rather lose than get a free pass into the World Cup final," van Niekerk said.

"I'm not going to sit here and lie and say we didn't think about (the weather). But we were here to play cricket.

"It's very upsetting. The team is quite distraught. It's the second time we have come really close in a semi-final. Everyone is hurting."

The result realistically keeps organisers' hopes alive of a record crowd of more than 90,000 at the MCG for the final, with Australia and India the competition's two biggest drawcards.

India beat Australia by 17 runs in the tournament opener, but the hosts look a far more settled team than they were a fortnight ago - even without the injured Ellyse Perry.

The team will face India in the big dance at the MCG. Image: AAP

Lanning looks close to her best, setting up the game with a measured 49 (not out) after openers Beth Mooney and Alyssa Healy had earlier come out swinging.

The pair whacked eight boundaries between them, both often using their feet with as Mooney hit 28 from 24 balls before being bowled by Nadine de Klerk.

Healy looked in good touch, twice jumping down the wicket to hit Chloe Tryon for four before she hit Ayabonga Khaka straight to mid-wicket on 18 from 13.

Lanning also opted to take on the spinners, hitting counterpart van Niekerk back over mid-off for six before acting as the aggressor again late.

It helped put Australia within touching distance of their fifth title in their sixth decider, while India will be playing in their first final.