World number one Simona Halep hit form to cruise past Venus Williams on Saturday and set up a mouth-watering Australian Open last 16 clash with her sister Serena Williams, who continued her near-flawless run in the first Slam of 2019.

Serena brushed aside Ukrainian teenager Dayana Yastremska in straight sets 6-2, 6-1 while the Romanian top seed defeated Venus 6-2, 6-3 in one hour 17 minutes in her best performance so far at this year’s tournament after the French Open champion struggled in the early rounds.

Japan’s Naomi Osaka survived a massive scare to reach the Australian Open fourth round Saturday despite an error-strewn display against Taiwanese veteran Hsieh Su-wei.

The 37-year-old Serena won her 23rd major Down Under two years ago and is the bookies’ favourite to claim an eighth Australian title, despite being seeded 16th.

Her latest victim Yastremska was not even born when the American won her first major at Flushing Meadows in 1999.

The 18-year-old was in tears after her drubbing and Williams comforted her at the net, telling her “you’re gonna make it, don’t cry”. “I thought she did really amazing,” Williams said of the youngster.

A bagel appeared imminent as Williams raced to a 4-0 lead but Yastremska managed to hold serve twice in the first set, prompting wild applause from the crowd.

She tried to engage Williams in rallies but was powerless to stop the American taking the first set 6-2 after 27 minutes.

Williams was equally relentless in the second set, breaking Yastremska and allowing the teen to score only four points off her serve as she went up 4-1.

Yastremska had treatment on her right foot but it was only delaying the inevitable and Williams took just a few minutes to bring up match point after play resumed.

Spain’s Garbine Muguruza said she narrowly avoided turning into a zombie before reaching the Australian Open last 16 after playing her previous match in the middle of the night.

The two-time Grand Slam winner, seeded 18, defeated Timea Bacsinszky of Switzerland 7-6 (7/5), 6-2 to make the fourth round at Melbourne Park.

The 25-year-old’s previous match against Briton Johanna Konta set a record for the latest start in the tournament’s history after it began in the early hours of Friday morning.

The clash, which Konta condemned as dangerous and unhealthy, began at 12:30 am and finished after a draining three sets at 3:12 am, the latest end to a women’s match at the Grand Slam.

Ukrainian sixth seed Elina Svitolina staged an epic fightback and shrugged off an injury scare with a three-set win against China’s Zhang Shuai.

Svitolina, who scored her biggest career win by clinching the WTA Finals in Singapore last October, received treatment on her neck and shoulder twice during the 4-6, 6-4, 7-5 victory.

She will meet 17th seeded American Madison Keys in the next round, who beat last year’s semi-finalist, 12ths eeded Elise Mertens, 6-3, 6-2

Osaka survives a scare

Osaka, 21-year-old US Open champion, seeded fourth at Melbourne Park, won the all-Asian clash 7-5, 4-6, 6-1 to set up a last 16 meeting with Latvia’s Anastasija Sevastova.

Osaka’s win equals her best performance at the Australian Open, where she reached the last 16 in 2018 but lost to world number one Simona Halep.

But she looked headed for the exit when she conceded the first set and was down 4-1 in the second before she won five straight games to force a decider.

“I just didn’t want to give up,” said Osaka, who made 42 unforced errors and received a code violation after throwing her racquet in the match. “I really love Grand Slams so I did anything I could do to stay here a bit longer.”

She started well, firing down two aces in her first service game before unleashing a backhand winner that left Hsieh wrong-footed.

But Hsieh pounced as the error-rate crept and the normally softly-spoken Osaka became agitated when she conceded three set points, dropping to her haunches as she tried to regain composure.

She saved one with an ace and managed to run Hsieh around to fend off another but hit a wild forehand over her opponent’s head on the third to go down a set.

The second set started badly for Osaka when she conceded an early break and then continued to struggle as Hsieh zipped around the court making stunning returns.

Osaka broke back against the run of play and built momentum with a crucial hold on break point before serving out the set on 42 minutes.

She fell heavily late in the set but shook off any discomfort and proceeded to open the final set with a break after smashing a sizzling cross-court backhand.

She held to go 2-0 up, extending her winning streak to seven games. Hsieh finally began to tire and the younger player was in control as she closed out the match.

Results - Women’s singles 3rd round

Naomi Osaka (JPN x4) bt Hsieh Su-wei (TPE x28) 5-7, 6-4, 6-1

Elina Svitolina (UKR x6) bt Shuai Zhang (CHN) 4-6, 6-4, 7-5

Anastasija Sevastova (LAT x13) bt Wang Qiang (CHN x21) 6-3, 6-3

Serena Williams (USA x16) bt Dayana Yastremska (UKR) 6-2, 6-1

Madison Keys (USA x17) bt Elise Mertens (BEL x12) 6-3, 6-2

(With AFP inputs)