Sabalenka serves up Open warning

Without a single double-fault, Aryna Sabalenka has served up the biggest warning yet to her Australian Open rivals.

The world No.5 continued her flawless start to the summer to roar into the third round at Melbourne Park with a 6-1 6-3 trouncing of dangerous American Shelby Rogers on Thursday.

The big-hitting Rogers, a former grand slam conqueror of Ash Barty, threatened a boilover early when she raced to a 3-1 lead on Rod Laver Arena.

But Sabalenka reeled off five straight games to snatch the second set and never looked back, running away with the match in one hour 27 minutes.

Tellingly, as well as showcasing the firepower that helped the Belarusian to last year's season-ending championship final in Texas and to this month's Adelaide International title, there were no signs of the serving yips that have undermined Sabalenka's progress on the big stages.

Much more significant than the three aces Sabalenka fired down and the loss of only one service game was the 25-year-old's effort in not coughing up a solitary double-fault.

The self-confessed "double-fault queen" racked up 428 last year, easily the most on the WTA Tour, including 19 alone in her corresponding second-round win in Melbourne 12 months ago.

So to say the fifth seed was over the moon with the improvement in what has been arguably women's tennis's greatest Achilles heel would be an understatement.

"Oh, my God, I did almost everything to try to fix my serve. Like, the whole year we were trying different things mentally, mental stuff, technique, technical, trying to breathe differently," Sabalenka said.

"I mean, I tried a lot. I was watching a lot of videos of my serve.

"You can't even imagine how much I worked. I'm just super happy right now that everything is working."

Yet to drop a set in six matches in 2023, the Open title chaser will play Belgian Elise Mertens next on Saturday for a place in the last 16 after the 26th seed ousted Hobart International winner Lauren Davis 6-4 6-3.

In the early hours of Friday morning, one of her rivals for the title, world No.2 Ons Jabeur, suffered a shock defeat to Marketa Vondrousova.

The Tunisian, a finalist at Wimbledon and the US Open in 2022, lost 6-1 5-7 6-1 to the unseeded Czech at Rod Laver Arena.

French world No.4 Caroline Garcia progressed, ousting former US Open finalist Leylah Fernandez 7-6 (7-5) 7-5 to book a third-round date with Laura Siegemund, a 5-7 7-5 6-3 upset winner over 27th seed Irina-Camelia Begu.

"I felt after I won the first set it was almost a little bit of robbery from my side because she was pretty much up all the time and was winning her service game very easily," Garcia said.

"I couldn't really find my rhythm but I tried to play one point at a time and stay in the moment."

Swiss 12th seed Belinda Bencic also advanced with a 7-6 (7-3) 6-3 win over rising American Claire Liu, while Russian 19th seed Ekaterina Alexandrova beat US wildcard Taylor Townsend 1-6 6-2 6-3.

But Alexandrova's ninth-seeded compatriot Veronika Kudermetova crashed out, succumbing to American qualifier Katie Volynets 6-4 2-6 6-2.