Naomi Osaka and Serena Williams stay on Australian Open collision course after third round wins

Japanese and American stars could meet in semi-finals but both face tough fourth round opponents

Naomi Osaka during her Australian Open third round match against Ons Jabeur. AFP

Naomi Osaka signs autographs after defeating Ons Jabeur in the third round match at the Australian Open. PA

Naomi Osaka serves to Ons Jabeur during their third round match at the Australian Open. AFP

Naomi Osaka hugs Ons Jabeur after their third round match on day five of the Australian Open. AFP

Serena Williams talks to the spectators after beating Anastasia Potapova on day five of the Australian Open. AFP

Serena Williams makes a backhand return to Anastasia Potapova. PA

Serena Williams makes a forehand return to Anastasia Potapova. PA

Serena Williams celebrates during her third round match against Anastasia Potapova. EPA

Garbine Muguruza serves to Zarina Diyas during their third round match at the Australian Open. AP

Garbine Muguruza hits a return to Zarina Diyas during their match on day five of the Australian Open. AFP

Aryna Sabalenka celebrates after defeating Ann Li in the third round at the Australian Open. PA

Aryna Sabalenka hits a return to Ann Li during their match on day five of the Australian Open. AFP

Su-Wei Hsieh celebrates winning her third round match against Sara Errani. Reuters

Su-Wei Hsieh hits a backhand during her third round match against Sara Errani. Reuters

Marketa Vondrousova hits a return to Sorana Cirstea during their match on day five of the Australian Open. AFP

Marketa Vondrousova reacts during her third round match against Sorana Cirstea. AP

Naomi Osaka sent out an ominous warning to her Australian Open rivals on Friday after defeating Tunisia's Ons Jabeur 6-3, 6-2 to reach the fourth round.

Third seed Osaka, the 2019 Australian Open champion, is yet to drop a set at this year's tournament, losing just 13 games in three matches, and she was again largely untroubled against the 27th seed.

The challenge steps up another level in the fourth round when the 23-year-old Japanese star faces last year's finalist Garbine Muguruza. The Spanish 14th seed and two-time major winner has also been in fine form Down Under and booked her meeting with Osaka with a 6-1, 6-1 thrashing of Kazakhstan's Zarina Diyas earlier in the day.

"I was really nervous and scared because I didn't know if she was gonna hit a drop shot on me, so I felt kind of rushed," Osaka said.

She also thanked the fans for attending on the day it was announced that Melbourne would go into five days' lockdown from midnight, meaning stands will be empty from Saturday.

"I hope that you guys enjoyed the match and thanks for coming out today."

If Osaka maintains her imperious form, a potential blockbuster semi-final could await with seven-time champion Serena Williams, who overcame some stubborn first set resistance from Anastasia Potapova to progress to the fourth round 7-6, 6-2.

Although it was not her best tennis on Friday, Williams gave the crowd ample suspense as she slumped to a 5-3 deficit in an error-strewn first set.

She survived two set points before getting the match back on serve when Potapova double-faulted. From there, it was all on Williams's terms.

"I wouldn't be in Australia if I didn't love what I do," said Williams, who is chasing a record-equalling 24th Grand Slam title.

"I think that love is one of the single greatest things in the world that you can have. It propels you to be your best in your job, whether it's playing tennis or whether it's doing something else."

However, if Williams is to maintain her pursuit of the major milestone, the 39-year-old American will need to avoid another slow start when she takes on seventh seed Aryna Sabalenka in the fourth round.

Sabalenka has lost just one of her past 19 matches – having claimed the last two titles of the 2020 season and this year's opening trophy at the Abu Dhabi WTA Women's Tennis Open – and the Belarusian was again unstoppable in the third round, cruising past American Ann Li 6-3, 6-1.

Also through to the fourth round on Friday, Taiwan's Su-Wei Hsieh followed up her win over ninth seed Bianca Andreescu with a 6-4, 2-6, 7-5 victory against Italy's Sara Errani. Her next opponent will be former French Open finalist Marketa Vondrousova after the Czech 19th seed defeated Romania's Sorana Cirstea 6-2, 6-4.