Gutsy Naomi Osaka saved two match points to outlast Garbine Muguruza in a tense comeback while Serena Williams was pushed to a decider but prevailed against Aryna Sabalenka in a thriller on Sunday and reach the Australian Open quarter-finals.
Hsieh Su-wei swept into her first Grand Slam quarter-final after 16 years of trying becoming the oldest player to make a last-eight debut in the Open Era. Later, Simona Halep fought back from a set down to beat French Open champion Iga Swiatek 3-6, 6-1, 6-4.
Third seed Osaka as on the verge of elimination at 3-5, 15-40 on her serve in the third set before rattling off four points in a row.
She then twice broke the serve of the two-time Grand Slam winner Muguruza to prevail 4-6, 6-4, 7-5 in one hour and 55 minutes of gripping action on an empty Rod Laver Arena, devoid of fans for the second day because of coronavirus restrictions.
Japan’s Osaka will now have an all-Asian quarter-final against Chinese Taipei veteran Hsieh Su-wei, who upset 19th seed Marketa Vondrousova 6-4, 6-2 in the fourth round.
The 2019 champion Osaka and Muguruza, last year’s runner-up, have five Grand Slam titles between them but surprisingly had never met on court before. Muguruza had been showing the form that saw her top-ranked in 2017 and she proved a formidable challenge for Osaka, widely deemed a title favourite at Melbourne Park.
A pumped-up Osaka went all out in an ultra-attacking start and took an early break as Muguruza lost serve for just the second time in the tournament. But a series of unforced errors allowed the composed Spaniard, who nailed 86% of her first serves, to level the score before she took a decisive break in the ninth game.
She again broke Osaka early in the opening game of the second with a superb lob winner. But the 2019 Australian Open champion settled, broke back in the fourth game and slowly wore down Muguruza to level the match.
The see-saw contest continued in a tense decider with Osaka unable to convert a break point in the fourth game only to subsequently drop her serve and slam her racquet to the ground in frustration. After saving the match points she clinched gritty victory with only a muted celebration on an almost silent Rod Laver Arena.
She now awaits another challenge in Hsieh Su-wei.
The 35-year-old overwhelmed Czech Marketa Vondrousova, a player 14 years her junior, in the Australian Open fourth round.
Hsieh got a early break in the opening set and never looked troubled in 6-4, 6-2 win over the 19th seed, a player she also toppled in an Abu Dhabi warm-up event in January.
Hsieh, by far the least decorated player left in her side of the draw, had already shown her mettle by beating 2019 US Open champion Bianca Andreescu en route to meeting Vondrousova. She made her Grand Slam debut in 2005 but had never gone beyond the fourth round before in 37 previous attempts.
Serena survives Sabalenka onslaught
Later, Serena Williams outlasted big-hitting Aryna Sabalenka in a three-set thriller to make Australian Open quarter-finals.
The American withstood a barrage from the seventh seed to prevail 6-4, 2-6, 6-4 in two hours and nine minutes and set up a mouth-watering clash with either world number two Simona Halep or French Open champion Iga Swiatek.
Williams, 39, had never before played the Belarusian, who has collected more trophies than anyone else since last year French Open but never reached the quarter-finals of a Slam. Sabalenka, who has spoken about modelling her big-hitting game on Williams, showed off her power with blistering serves and groundstrokes in the high-octane contest.
A composed Williams, watched by older sister Venus in the stands, counter-attacked superbly in the early stages and broke Sabalenka’s serve in the 10th game to win the opening set.
Sabalenka, who was born four months after Williams made her Grand Slam debut in 1998, was unperturbed and stepped up her assault to dominate Williams’s usually reliable serve.
The 22-year-old admonished herself before drawing level by pouncing on Williams’s faltering first serve, which she landed just 36% of the time in the second set.
Williams regrouped and raced to a commanding 4-1 lead in the third set as a frustrated Sabalenka slammed her racquet to the ground as the match began to slip away.
Sabalenka won three straight games to get back on terms but Williams’s experience saw her through as she maintained her unbeaten run since emerging from 14-day quarantine in Australia.
Halep gains revenge on Swiatek
Halep exacted revenge on Swiatek with a comeback three-set victory, which set up a blockbuster quarter-final with Serena Williams.
The world No 2 was thrashed by the 19-year-old at Roland Garros, winning just three games, but turned the tide in Melbburne.
Halep was aggressive early, but 15th seed Swiatek showcased remarkable defensive skills, thwarting the attacks with sliding retrievals along the baseline.
The Romanian rued squandering two break points in the seventh game and she then played a loose service game to hand the initiative to an increasingly confident Swiatek, who claimed her 21st consecutive set in a Grand Slam.
Halep, whose seven-year streak in the top 10 is the longest active run among women, lifted her intensity and relentlessly hit the lines to force a ragged Swiatek into errors.
Swiatek’s confidence was dented and she lost her serve in the third set’s opening game with a double fault, but fought back to level up with a break in the fourth game.
She was unable to consolidate, dropping serve to love, as Halep calmly clinched a quarter-final berth.
Halep, 29, is seeking a maiden triumph at Melbourne Park having fallen short to Caroline Wozniacki in the 2018 decider. She was left stunned last year after a straight-sets loss to Garbine Muguruza in the semi-finals.
With AFP Inputs
Women’s singles fourth round:
Hsieh Su-wei (TPE) bt Marketa Vondrousova (CZE x19) 6-4, 6-2
Naomi Osaka (JPN x3) bt Garbine Muguruza (ESP x14) 4-6, 6-4, 7-5
Serena Williams (USA x10) bt Aryna Sabalenka (BLR x7) 6-4, 2-6, 6-4
Simona Halep (ROM x2) bt Iga Swiatek (POL x15) 3-6, 6-1, 6-4