Later, a highly anticipated quarter-final clash will take place between Novak Djokovic and Carlos Alcaraz, with the winner set to face world number two Alexander Zverev.
As the top seed, Sabalenka is vying for her third consecutive Australian Open title, a feat last accomplished by Martina Hingis 26 years ago.
The Belarusian managed to keep her title hopes alive, overcoming Russian 27th seed Anastasia Pavlyuchenkova with a score of 6-2, 2-6, 6-3.
At 33, Pavlyuchenkova has been experiencing a resurgence in her career and was the oldest player remaining in the tournament.
In the semi-finals, Sabalenka will compete against Badosa, who achieved a significant milestone by defeating world number three Gauff 7-5, 6-4 on Rod Laver Arena, marking her first Grand Slam semi-final appearance at the age of 27.
“I’m a bit emotional,” said Badosa. “I’m a very emotional person. I wanted to play my best game. I think I did it.
“I’m super proud of the level I gave today.”
The eleventh seed completed a remarkable comeback, having been ranked outside the top 100 just a year prior due to a stress fracture.
“I mean, a year ago, I was here with my back that I didn’t know if I had to retire from this sport, and now I’m here playing against the best in the world,” said Badosa.
Third-seeded American Gauff entered the match with an impressive nine-match winning streak this season, but she faced a formidable opponent in the Spaniard.
The 20-year-old former US Open champion found herself under immediate pressure in the first set from the aggressive Badosa, which established the match's intensity. Gauff expressed her feelings as “disappointed but not entirely defeated.”
In prime-time action, Germany’s Zverev triumphed over American Tommy Paul with a score of 7-6 (7/1), 7-6 (7/0), 2-6, 6-1, advancing in his pursuit of a first Grand Slam title.
The 27-year-old experienced a moment of distraction when a feather floated across the court at Rod Laver Arena, nearly causing him to lose his composure.
The umpire intervened, calling for a replay as the feather drifted into his line of play during a critical break point.
“C’mon, that is unbelievable on break point,” he shouted, before taking out his fury on Paul by breaking to love.
Zverev demonstrated his decisiveness during the tiebreaks and, despite experiencing a dip in performance in the third set, he quickly regained control to secure victory in the fourth set.
As Zverev prepares for his next match, he will be among those watching the highly anticipated showdown between Alcaraz, 21, and Djokovic, 37, on the Rod Laver Arena.
Djokovic aims to achieve his 100th tournament title and a historic 25th Grand Slam title. He declined to participate in a standard on-court interview on Sunday, expressing his discontent with a TV presenter from Channel Nine, whom he accused of making “insulting and offensive comments.”
In their head-to-head record, Djokovic holds a slight advantage at 4-3, having triumphed over Alcaraz in their last encounter at the Paris Olympics final.
However, Alcaraz has emerged victorious in their last two Grand Slam meetings, winning the finals at Wimbledon in both 2023 and 2024, and he is already a four-time major champion. Nevertheless, he has yet to advance past the quarter-finals at the Australian Open.
Djokovic anticipates a “big battle” against the successor to Spanish tennis icon Rafael Nadal.
Alcaraz remains cautious, recognizing that the seasoned Serbian still possesses significant skill, especially on his preferred court where he has claimed the title ten times.
“When we are seeing him playing, he seems like he’s young again, it’s unbelievable,” said Alcaraz.