OMNISPORT

None of 2017's grand slam winners will be in the Australian Open fourth round after Jelena Ostapenko was beaten by Anett Kontaveit on day five.

Serena Williams' withdrawal prior to the tournament only left three in action, and Ostapenko was the only one standing in round three after Sloane Stephens and Garbine Muguruza made early exits.

However, French Open champion Ostapenko, who needed a medical timeout for a thigh injury, was soon following them as she was beaten in three sets by Kontaveit on Friday.

That leaves only two grand slam winners in the draw – Maria Sharapova and Angelique Kerber – but that will be down to one given they meet each other in round three.

With the draw wide open, Caroline Wozniacki staked her claim with a hard-fought 6-4 6-3 win over Kiki Bertens, while Elina Svitolina also eased into round four with victory over youngster Marta Kostyuk.

Fellow seed Magdalena Rybarikova is also through after a 7-5 3-6 6-1 triumph over Kateryna Bondarenko.

"I'M PLAYING WITH HOUSE MONEY"

Wozniacki was facing elimination in the second round against Jana Fett, the Dane having to save two match points and come from 5-1 down in the deciding set to progress.

There were no such problems against Bertens, though, her straight-sets win taking 86 minutes.

She had some frustrations during the victory but was delighted to have made the fourth round for the first time since 2013, and says there is no pressure on her shoulders.

"I'm playing with house money," she said, referring to almost exiting the tournament against Fett. "I have nothing to lose.

"I have a second chance and I will see how far I can go."

MARTIC BLOCKS OUT THE BLISTERS

Petra Martic saw off Luksika Kumkhum to book her fourth appearance in the fourth round of a grand slam, the Croatian needing painkillers to fight blisters caused by the Melbourne conditions.

Martic - celebrating her 27th birthday on Friday - set up a meeting with Elise Mertens with a 6-3 3-6 7-5 win on Friday but, like Muguruza before her, was hampered by blisters caused by the heat coming through the court.

"I got some blisters and I took painkillers after the second set, because it really made it difficult for me to move," she said. "It's really tough on your feet to play in these conditions."

SVITOLINA UNFAZED BY FAVOURITE TAG

With a number of top seeds already out of the women's draw, Svitolina has emerged as a favourite for the title after moving into round four.

The world number four eased past fellow Ukrainian Kostyuk 6-2 6-2 on Friday and had having no problems against her 15-year-old opponent.

When asked if being spoken about as a potential champion bothered her, the fourth seed insisted it had no effect on her game.

Svitolina said: "Of course, it adds a little bit more pressure, but when you are out there playing on the court, I don't have this thing in my head. I just have my opponent, I have my racquet, tennis ball, and I know what I have to do."

KOSTYUK ENJOYS FREE SVITOLINA LESSON

Teenager Kostyuk made her main draw debut at a grand slam at Melbourne Park after beating Arina Rodionova, Daniela Seguel and Barbora Krejcikova in qualifying.

That made her the first player born in 2002 to make the first round, and her impressive run continued with victories over Shaui Peng and Olivia Rogowska – Kostyuk setting records as she went.

Getting past compatriot Svitolina proved a step too far, though, but the 15-year-old was not too downbeat and an experience of a lifetime.

"[I took] a lot [from the match]," she told a media conference. "How much [would] you have to pay Svitolina to have a one-hour lesson? So I got it for free.

"She is incredible, she's a god."