Aryna Sabalenka and Coco Gauff both did it the hard way as the Australian Open favourites scraped into round four at Melbourne Park.

Sabalenka, who is searching for her third Australian Open crown, was pushed all the way by Anastasia Potapova, eventually prevailing 7-6 (7-4) 7-6 (9-7).

The world number one seemed on course for an emphatic win when she cruised into a 4-0 lead in the second set, having wrestled control of the tie-break in a cagey opener.

Yet Potapova fought back valiantly, winning four straight games. Sabalenka broke back to end her opponent's streak, but then immediately lost her serve.

Sabalenka eventually regained her composure to triumph in an epic tie-break.

13 - Aryna Sabalenka has reached the R4 in each of her last 13 Grand Slam appearances: the first player to achieve the feat in Women’s Singles Majors since Serena Williams (14 in a row between the US Open 2014 and the Australian Open 2019). Model.#AusOpen | @AustralianOpen @WTA pic.twitter.com/HxiYoPv8j4

— OptaAce (@OptaAce) January 23, 2026

"Aryna five years ago would be focusing too much on the way she feels and completely lose these matches," Sabalenka said.

"I learned that it doesn't really matter how you feel, it's all about your mentality, your mental strength to be there, try your best, return the ball ugly with terrible technique and your body being completely disconnected. When you see that things are not working, the only tactic you have is to fight. 

"I'm super happy with my mentality today. I think it was the only thing that really helped me get the win. It was one of those days you have to fight to try and get the ball back. Emotionally, I was all over the place. I was trying to figure out how to connect my body.

"It seemed like everything was working separately; my brain was somewhere else, my arms were going one direction. Magically, I was able to get this win."

Sabalenka's reward is a fourth-round meeting with teenage sensation Victoria Mboko, who defeated Clara Tauson 7-6 (7-5) 5-7 6-3.

Mboko is the first Canadian woman to reach the fourth round of a major since Leylah Fernandez at Roland-Garros in 2022, and the first at the Australian Open since Eugenie Bouchard in 2015.

Gauff also found life difficult, as the two-time grand slam champion needed three sets to overcome compatriot Hailey Baptiste 3-6 6-0 6-3.

77 - Among current players, only Venus Williams (85) and Iga Swiatek (83) have more Women’s Singles Major’s matches than Coco Gauff (77) after 100 played - equalling Aryna Sabalenka. Elite.#AusOpen | @AustralianOpen @WTA pic.twitter.com/Xp56ofdMO9

— OptaAce (@OptaAce) January 23, 2026

Jasmine Paolini, meanwhile, was a big-name exit, with the world number eight losing 6-2 7-6 (7-3) to 18-year-old Iva Jovic, who is the first player to claim 10 WTA-level main draw wins in 2026.

Data Debrief: Century up for Gauff

Gauff became the youngest woman to appear in 100 grand slam main draw matches since Maria Sharapova at the French Open 2008.

She marked the occasion by claiming her 77th win. Among active players, only Venus Williams (85) and Iga Swiatek (83) have won more of their first 100 major matches.

Sabalenka, meanwhile, has won her last 19 grand slam tie-breaks, the longest such winning streak in the Open Era.

The top seed has reached the fourth round in each of her last 13 major appearances. She is the first woman to achieve the feat since Serena Williams (14 in a row between the 2014 US Open and the 2019 Australian Open).