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. Also, 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.
She 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 35-year-old overwhelmed Vondrousova, a player 14 years her junior. Hsieh got a early break in the opening set and never looked troubled in win over the 19th seed, a player she also toppled in an Abu Dhabi warm-up event in January.
Serena survives onslaught
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 world number two Simona Halep.
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’ 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 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.