Serena Williams crushed Ukrainian teenager Dayana Yastremska 6-2, 6-1 as she marched towards an eighth Australian Open title.

Serena Williams of the US in action during the match against Ukraine's Dayana Yastremska at the Melbourne Park, Melbourne, Australia, January 19, 2019.
Serena Williams of the US in action during the match against Ukraine's Dayana Yastremska at the Melbourne Park, Melbourne, Australia, January 19, 2019. (Reuters)

Serena Williams' relentless drive towards an eighth Australian Open title cranked up another gear Saturday with a third round drubbing, as Naomi Osaka and Elina Svitolina survived big scares to stay in the hunt.

On day six at Melbourne Park, the 23-time Grand Slam winner crushed Ukrainian teenager Dayana Yastremska 6-2, 6-1 before consoling her at the net as she burst into tears.

The 37-year-old, seeded 16, has dropped just nine games in her three matches so far and with face either sister Venus or world number one Simona Halep for a berth in the quarter-finals.

"I just play each match at a time, play as hard as I can and do the best I can. That really is all you can do," she said about her form so far.

She also had some words of encouragement for 18-year-old Yastremska.

"She was amazing, she came out swinging. To be so young she came out ready to go."

Next up could be misfiring Halep, who is returning from a herniated disc and has limped through her first two matches at Melbourne Park, taken to three sets in both.

Or it may be her sister, who is still going strong 21 years after playing for the first time in Melbourne.

Fourth-seeded Osaka looked down and out against Taiwanese veteran Hsieh Su-wei before battling back to win 7-5, 4-6, 6-1 and set up a last 16 meeting with Latvia's Anastasija Sevastova, who beat China's Wang Qiang in straight sets.

Osaka's win equals the 21-year-old's best performance at the Australian Open, where she reached the last 16 in 2018 but lost to Halep.

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

"I just didn't want to give up," said the Japanese, who made 42 unforced errors and received a code violation after throwing her racquet.

"I really love Grand Slams so I did anything I could do to stay here a bit longer."

Pliskova struggled with a painful shoulder complaint that required treatment at every changeover, and medical timeouts, before somehow beating China's Zhang Shuai 4-6, 6-4, 7-5 as the temperature rose in the centre court sunshine.

'Die or win'

"It was very hot conditions, I was struggling a little bit. We left everything on court today," said. Svitolina, who scored her biggest career win by clinching the WTA Finals in Singapore last October.

"We practise every day for these kind of matches," she added, watched by boyfriend Gael Monfils. "I just told myself 'you're going to die or win'."

She will meet either Belgian 12th seed Elise Mertens or 17th seeded American Madison Keys in the next round.

Fourteen-time Grand Slam winner and top seed Novak Djokovic is gunning for a seventh Melbourne Park title and faces 25th-seeded Canadian Denis Shapovalov later, one of the NextGen stars who are out to topple the sport's big guns.

Whoever wins will face 15th seed Daniil Medvedev, who eased past 21st seed David Goffin, with the Russian dark horse yet to drop a set at the tournament.

Eighth seed Kei Nishikori made it back-to-back victories for Japan by beating Portugal's 44th-ranked Joao Sousa 7-6 (8/6), 6-1, 6-2.

The 29-year-old has won all three of his first week matches on Margaret Court Arena to reach the last 16 for the seventh time in nine appearances.

"I love to play this court, I'm very comfortable here," said the 2014 US Open finalist after delighting a large contingent of Japanese fans.

"It's great to play here, especially after Naomi today."

He next plays either 23rd seed Pablo Carreno Busta of Spain or Italy's Fabio Fognini, seeded 12.

Source: AFP