MELBOURNE, Jan 21, 2024 (BSS/AFP) - Aryna Sabalenka and Coco Gauff powered into the Australian Open quarter-finals on Sunday with ruthless straight-sets wins as world number one Novak Djokovic attempted to do the same against Adrian Mannarino.

Defending champion Sabalenka has been in imperious touch in Melbourne and was again dominant against unseeded Amanda Anisimova on Margaret Court Arena, sweeping past the American 6-3, 6-2.

Fourth seed Gauff, attempting to become the first woman to back up a US Open title with a Grand Slam win in Australia since Naomi Osaka in 2018-19, has been almost as impressive.

She swatted aside Poland's unseeded Magdalena Frech 6-1, 6-2 in just 63 minutes on Rod Laver Arena, with the 85-year-tennis legend watching from the stands.

"There is no better court in Australia than Rod Laver," said 19-year-old Gauff, who had never progressed beyond the fourth round at Melbourne Park in four previous attempts.

"It was an honour to play in front of you, so thank you for coming to my match."

With seven of the women's top 10 seeds knocked out in the first week, including world number one Iga Swiatek, both Gauff and Sabalenka have a glorious chance to win their second major title.

They are on the same side of the draw and will not meet in the final, with a potential last-four clash looming instead.

Sabalenka has dropped just 11 games in four matches and is favourite to win another title to go with her breakthrough Grand Slam crown last year.

Should she go all the way, the 25-year-old will be the first woman to retain the title since compatriot Victoria Azarenka completed the feat in 2013.

"I'm getting stronger because I enjoy the atmosphere and I really want to stay here as long as I can till the very last day," she said.

Her next opponent will be unseeded Russian 16-year-old Mirra Andreeva or ninth seed Barbora Krejcikova.

If Andreeva keeps her dream run going, she will become the youngest woman to reach the Melbourne Park quarter-finals since Martina Hingis in 1997, a player she has often been compared to.

Ukraine's Marta Kostyuk takes on another Russian, qualifier Maria Timofeeva, in the other fourth-round clash for the right to meet Gauff.

- Things will improve -

Top seed Djokovic recaptured his top form to surge into the last 16 after dropping sets in his opening two matches, and believes he will only get better as he chases an 11th title.

"Coming into the tournament I haven't really felt great health-wise, physically, and also game-wise. It's all connected obviously," said the Serb, who is gunning for a record 25th Grand Slam crown.

"But I'm in the fourth round. I believe that things will progress as the tournament goes on."

That will be a worry for Mannarino, who at 35, is a year younger than his Serbian opponent and enjoying a late career resurgence.

The pair have met four times before, but not since 2018, with Djokovic winning each time.

Djokovic almost always plays the night session on Rod Laver Arena, but has been bumped to the afternoon this time.

That's because home hope Alex de Minaur, seeded 10, is bidding to make the last eight for the first time, with Russian fifth seed Andrey Rublev standing in his way.

In other fourth-round action, in-form fourth seed Jannik Sinner faces last year's semi-finalist Karen Khachanov.

The man who beat him in that semi-final, Stefanos Tsitsipas, who is the seventh seed, takes on 12th-seeded American Taylor Fritz.