Defending champion Aryna Sabalenka put her close friendship with Paula Badosa aside Thursday to sweep past the Spaniard into a third successive Australian Open final and stay on track for a 26-year first.

The Belarusian world number one romped home 6 - 4, 6 - 2 on Rod Laver Arena and will meet either Polish second seed Iga Swiatek or American 19th seed Madison Keys in Saturday's decider.

The hard, fast courts of Melbourne Park have been the 26-year-old's happy place.

She has now won 20 straight matches at the Australian Open to close in on a third consecutive crown — something that hasn't happened this century.

The last person to achieve the feat was Martina Hingis in 1999 and only four other women have completed the three-peat — Margaret Court, Evonne Goolagong, Steffi Graf and Monica Seles.

Court was in the stadium watching.

"Honestly, I don't know. I'm so proud of myself. I'm proud of my team that we're able to put ourselves in such a situation," Sabalenka said of being on the cusp of a third title.

"It's a privilege, you know. If I'm able to put my name into history, it will mean a lot. It will mean the world to me."

Sabalenka last year described Badosa as her "best friend" and "soulmate" and said she was "super happy" that they got to play each other on such a big stage.

"A tough match, tough battle," she said.

"I hope she's still my friend. I'm sure she'll hate me for the next hour, day or two, but I'm okay with that, I can handle that."

"After that I think we are back to being friends, back to go out together and go shopping."

Despite their friendship, it was all business on a cool Melbourne evening.

The 11th seed Badosa stunned world number three Coco Gauff in straight sets to reach her maiden Slam semi-final at the age of 27 and came out swinging.

She gifted Sabalenka a break point in the opening game on a double fault, but then nailed some big winners to save and hang on.

It was then the Belarusian's turn to offer two break points to the Spaniard with some sloppy power shots and Badosa capitalised to open a 2 - 0 lead when a forehand sprayed wide.

But the top seed found her radar and rallied from 0 - 40 down on Badosa's next serve to break back as her opponent's error count mounted.

Sabalenka then won three games in a row to surge 4 - 2 clear as Badosa fluffed some vital shots.

With rain arriving the roof was closed, but it didn't halt the Sabalenka juggernaut, wrapping up the set in 53 minutes with an ace, slapping 19 winners to Badosa's six.

Badosa tumbled to the floor early in set two as she reached for a shot, before giving the thumbs up, with the action briefly delayed as both players burst out laughing.

Sabalenka composed herself and broke for a 2 - 1 lead when Badosa sent down consecutive double faults, then broke again with the Spaniard having no answer to her bruising baseline game.

The win kept alive Sabalenka's quest to still be world number one when she leaves Melbourne.

If she had lost, Swiatek would have taken it back. Should the pair meet in the final, the winner will depart the tournament with the top ranking.

Despite losing, Badosa's run to the last four capped a remarkable comeback.

A former world number two, she spent several months out after a brutal back injury in 2023 and last year considered quitting tennis.

Instead, her Melbourne exploits will return her to the top 10 for the first time since October 2022.