World number one Aryna Sabalenka powered past Chinese qualifier Bai Zhuoxuan on a day four where men's top seed Carlos Alcaraz made another step towards his maiden Australian Open title.

In warm conditions in Melbourne on Wednesday, Bai was China's sole singles player in action and had the daunting task of facing two-time Australian Open champion Sabalenka in the round of 64.

Belarus' Aryna Sabalenka (R) shakes hands with China's Bai Zhuoxuan after Sabalenka's victory in their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 21, 2026. (Photo: AFP)

The 23-year-old Bai did win three games in a brief first set comeback, but Sabalenka was never seriously troubled in her 6-3, 6-1 victory in one hour and 16 minutes.

Bai's stirring run at Melbourne Park ended after four straight victories, including edging Anastasia Pavlyuchenkova in a three-set thriller in the first round.

"I feel great, happy to get the win against a tricky opponent," said Sabalenka, a four-time grand slam champion.

Sabalenka next faces Anastasia Potapova, who upset 2021 US Open champion Emma Raducanu.

American third seed Coco Gauff demolished Olga Danilovic 6-2, 6-2 in an eye-catching performance marked by 14 winners, including several well-executed drop shots.

USA's Coco Gauff hits a return to Serbia's Olga Danilovic during their women's singles match on day four of the Australian Open tennis tournament in Melbourne on January 21, 2026. (Photo: AFP)

Gauff had a significantly improved performance after an error-strewn first round win over Uzbekistan's Kamilla Rakhimova.

"Today felt a bit better, I felt better off the serve for sure, and off the ground," Gauff said.

It was a disappointment for 69th-ranked Danilovic, who emerged triumphant against 45-year-old Venus Williams in a first round classic.

Gauff will play compatriot Hailey Baptiste in the third round.

Two-time grand slam finalist Jasmine Paolini, eighth seed Mirra Andreeva and Ukrainian veteran Elina Svitolina were also among the winners.

In the men's action, Alcaraz overcame German Yannick Hanfmann 7-6 (4), 6-3, 6-2 in a hard-fought clash in two hours and 44 minutes.

Spain's Carlos Alcaraz hits a return to Germany's Yannick Hanfmann during their men's singles match on day four of the Australian Open tennis tournament in Melbourne on January 21, 2026. (Photo: AFP)

"I knew he was going to play great. I'm really happy to get through a really difficult first set and then played much better," said Alcaraz, who hit 41 winners and will next face 32nd seed Corentin Moutet after qualifier Michael Zheng retired hurt.

In the night session on Rod Laver Arena, third seed Alexander Zverev overcame an injury scare in his battling four-set victory over France's Alexandre Muller.

The German finally prevailed 6-3, 4-6, 6-3, 6-4 in just over three hours on the back of his four-set victory over Gabriel Diallo in the first round.

Zverev, last year's beaten finalist, required medical attention in the fourth set for a leg injury and he needed a painkiller to get through the match.

"I'm extremely happy with this match. This is my favorite court," Zverev said.

Australia's title hope Alex de Minaur rallied after losing the opening set to defeat Hamad Medjedovic 6-7(5), 6-2, 6-2, 6-1.

"I'm super happy with my level. The competition is only going to get tougher and I'm up for the challenge," said sixth seed de Minaur, who is bidding to end Australia's 50-year title drought in the men's singles on home soil.

Andrey Rublev and Daniil Medvedev also made it through to the third round.

In the women's doubles, China's Xu Yifan and Yang Zhaoxuan beat Antonia Ruzic and Renata Zarazua in straight sets.

China's Zhang Shuai partnered with Elise Mertens of Belgium to sweep aside Sorana Cirstea and Anna Kalinskaya.

But Chinese pair Wang Xinyu and Zheng Saisai fell to Lizette Cabrera and Taylah Preston in straight sets, while Shang Juncheng and Zhang Zhizhen lost a tense three-set battle to Matthew Ebden and Rajeev Ram in the men's doubles.

On Thursday, the men's draw is highlighted by the second round matches of defending champion Jannik Sinner and 24-time grand slam winner Novak Djokovic.

Women's world No.2 Iga Swiatek will also be in action on day five along with defending champion Madison Keys.

Wang, Shang and Wu Yibing, the last Chinese players remaining in the singles, will be aiming to reach the third round.