MELBOURNE, Jan 23, 2026 (AFP) - Aryna Sabalenka said she was "emotionally all over the place" as she was forced to dig deep to reach the last 16 on Friday at the Australian Open, where Carlos Alcaraz will resume his quest for a maiden Melbourne title.

Also in action on day six at Melbourne Park are third seeds Coco Gauff and Alexander Zverev, and former runner-up Daniil Medvedev.

Belarusian world number one Sabalenka is attempting to win the title for a third time in four years, having been stunned in last year's final by Madison Keys.

But she did not have it at all easy against unseeded Russian-born Anastasia Potapova of Austria, pulling through 7-6 (7/4), 7-6 (9/7) in just over two nervy hours at a sunny Rod Laver Arena.

"I was always on the back foot, one of those days you have to fight to try and get the ball back," said the top seed.

"Emotionally I was all over the place," added the 27-year-old four-time Grand Slam champion, who faces Canadian teenager Victoria Mboko for a place in the quarter-finals.

"It was such a fight and I really enjoyed it."

The 19-year-old Mboko defeated Clara Tauson of Denmark 7-6 (7/5), 5-7, 6-3.

Gauff has been mostly impressive so far, saying she was "near perfect" in making the third round.

The 21-year-old has won the US Open and French Open, but her best performance in Melbourne is the semi-finals.

She faces fellow American Hailey Baptiste, ranked 70, while fast-rising Russian eighth seed Mirra Andreeva plays Romania's Elena-Gabriela Ruse.

Jasmine Paolini, the seventh seed from Italy, comes up against dangerous United States teenager Iva Jovic.

- Alcaraz faces test -

Men's top seed Alcaraz came through a tough three-set arm-wrestle in round two and faces another tricky task against French 32nd seed Corentin Moutet.

The 22-year-old Spaniard is bidding for a career Grand Slam of all four majors.

He said his testing 7-6 (7/4), 6-3, 6-2 victory over Yannick Hanfmann in round two had served him well.

"I'm still getting used to the conditions, getting used to playing better," said the six-time Grand Slam winner.

"Just happy that I'm just improving every day after every match. So hopefully being better in the next round."

Alcaraz has never gone past the quarter-finals in his four trips to Australia.

Should he beat Moutet, he will meet either American 19th seed Tommy Paul or Spanish 14th seed Alejandro Davidovich Fokina to make the last eight once again.

Germany's Zverev, well beaten by Jannik Sinner in last year's final, dropped a set in both his opening two matches and will have an evening clash against British 26th seed Cameron Norrie.

Home hope and sixth seed Alex de Minaur has again been awarded the prime time night slot on Rod Laver Arena.

This time he will encounter the dangerous American Frances Tiafoe, who made the Melbourne quarter-finals in 2019 before losing to Rafael Nadal.

Russia's Medvedev, a three-time losing finalist in Melbourne, faces a tricky encounter against Hungary's Fabian Marozsan.