Sabalenka, Halep sweep into last 16

World number two Aryna Sabalenka cleaned up her serving woes to stay in contention at the Australian Open Saturday, but she needed three sets to get past 31st seed Marketa Vondrousova.

The Belarussian had tallied 31 double faults in two matches at Melbourne Park so far, and 70 from four matches this season, but only suffered 10 against the Czech to win 4-6, 6-3, 6-1 on Margaret Court Arena.

It was enough to ensure passage to the last 16 where she will meet unseeded Estonian veteran Kaia Kanepi who overpowered Australian wildcard Madison Inglis 2-6, 6-2, 6-0.

The Australian Open is the only major where the 115th-ranked Kanepi, 36, has failed to make the quarter-finals.

“I'm really happy right now and mostly happy that I made only 10 double faults,” said Sabalenka, a semi-finalist last year at both Wimbledon and the US Open.

“She played unbelievable tennis today and I pushed myself really hard. I'll just keep working on my serve and keep hoping it gets better match-by-match.”

Despite her serving yips, Sabalenka found a way to survive her opening two rounds against players ranked in triple digits thanks to her explosive all-court ability.

She brought that to the fore again against Vondrousova after early wobbles.

On a hot day with ice packs out at the changeovers, Vondrousova took a 5-3 lead the first set and while Sabalenka only sent down four double faults she couldn't turn it around.

Sabalenka also lost the first set in her opening two rounds but found a way back and the 23-year-old responded with the same fighting spirit, immediately breaking the Czech to race 3-0 clear in set two.

She held firm, firing just three double faults, to seal the set and turned up the pressure on Vondrousova with an early break to move 3-1 clear in the third. Two more breaks enabled her to romp to victory.

Meanwhile, the early action on Saturday was dominated by the resurgent former finalist Simona Halep, who swept into the second week in Melbourne.

Halep swatted aside Danka Kovinic, the conqueror of US Open champion Emma Raducanu, 6-2, 6-1 in just 64 minutes and will face French veteran Alize Cornet on Monday for a place in the quarter-final.

The fit-again Halep came into the tournament full of confidence after her first title in 16 months earlier this month at a Melbourne warm-up event and was always in charge.

“I feel great that I can play the fourth round again. I always love to play in Australia so that's why maybe I play good matches,” said Halep.

Seeded 14, Halep has been in insatiable form, dropping just nine games in her opening two matches, and she carried it into her clash against the 27-year-old. 

Cornet slugged it out with Slovenia's 29th seed Tamara Zidansek for a 4-6, 6-4, 6-2 victory and said she was just glad to get through on a hot day.

“It was mostly about survival,” said Cornet, who produced a stunning upset of world number three Garbine Muguruza in round two.

American world number 30 Danielle Collins, who seems to raise her game in Melbourne where she was a semi-finalist three years ago, is also through to the last 16 after battling past tenacious Danish teenager Carla Tauson 4-6, 6-4, 7-5.

Collins, the 27th seed, was a set and 1-3 down against the emerging star before fighting back.

“It was a long battle and super happy to be able to pull it out,” said Collins.

She now has a last-16 clash against the 2018 semi-finalist Elise Mertens, after the Belgium 19th-seed cruised past China's Zhang Shuai 6-2, 6-2.