Swiatek, Svitolina, Keys, Sonego and Shelton also reached the Grand Slam quarterfinals on a hot day in Melbourne.

Defending champion Jannik Sinner has battled illness to reach the quarter-finals of the Australian Open, but the physical demands of Grand Slam tennis are proving difficult for French veterans Gael Monfils and It was too much for American youngster Lerner Tian.

Iga Swiatek was in superb form as she beat lucky loser Eva Lys 6-0 6-1 on Monday to continue her bid for a first title and sixth at Melbourne Park Grand Slam champion but Elena Rybakina couldn’t shake off back problems and fell 6-6. 3 1-6 6-3 to Madison Keys.

The 38-year-old Monfils, who was forced to retire due to back problems, ended up trailing young American Ben Shelton 7-6(3) 6-7(3) 7-6(2) 1-0. A grand slam after the Auckland win in the first inspired game of the year.

The sweltering heat didn’t do defending champion Sinner any favors as he began to struggle physically in the second set of his fourth-round match against Dane Holger Ruane on Rod Laver Arena.

The top seed did not want to elaborate on his condition but admitted to experiencing symptoms of dizziness before a lengthy medical pause in the third set that proved a turning point in his 6-3 3-6 6-3 6-2 victory.

“I don’t feel good,” said the 23-year-old Sinner, who reached his 10th Grand Slam quarter-final and equaled the Italian record set by Nicky Pietrangeli. “I think we saw that today, my body struggled.”

Sinner will next face home hope Alex De Minaur, who made his Australian debut with a 6-0 7-6(5) 6-3 victory over American Alex Michelson. Open Quarterfinals.

“What I want most is to play well in Australia. I’m happy that I finally made it to the quarter-finals here, but yes, let’s pursue bigger and better things, come on!” said eighth seed De Mina Er said after the night match at Rod Laver Arena.

Unseeded Lorenzo Sonego defeated hobbled 19-year-old American qualifier Tien 6-3 6-2 3-6 6-1 in the quarterfinals , and eliminated the young Brazilian player Joao Fonseca in the second round, breaking into the Italian team twice.

“I’m sad he’s having problems,” said the 29-year-old Sonego, who has never gone this deep in a major before and faces Shelton next.

“That’s not the right way to win.”

Tenn, hoping to become the youngest player to reach the quarter-finals since 17-year-old Goran Ivanisevic in 1989, stretched his strapped right thigh after a double fault and never looked physically fit. Comfortable.

Ivanisevic was part of Rybakina’s team at Melbourne Park and her coach Stefano Vukov was banned from competing by the WTA over possible breaches of the code of conduct.

The former Wimbledon champion said it was not an ideal situation and she was still experiencing back problems but was not looking for anything after losing to Keys in a roller-coaster match at Margaret Court Arena Excuse.

“I had some chances, but that’s what it is,” said the disappointed sixth seed. “I need to work better.”

Keys will next face familiar opponent Elina Svitolina, who defeated Russia’s Veronika Kudermetova 6-4 6-1 in her first singles match (Veronika Kudermetova), bringing “a little light” to war-torn Ukraine.

The 30-year-old Ukrainian fell behind 4-1 in the first set, but rallied to win easily, writing a “Spirit of Ukraine” message in front of the camera before leaving the court.

“I was very eager to win today and let the Ukrainian people know the good news,” Svitolina said.

Svitolina refused to shake hands with her opponents after the match, as was the case with all Ukrainian players facing the Russians because of the war between the two countries.

“For me to find a way to win, to find a way to bring a little bit of light, a little bit of victory to the Ukrainian people, I feel like I have a responsibility.”

Svitolina later returned to the Margaret Court Arena to cheer on her husband Monfils, but there was no double joy.

That was reserved for Swiatek, who received news after her victory that WADA would not appeal her doping case to the Court of Arbitration for Sport after she tested positive for trimetazidine last year.

The Pole accepted a one-month ban after explaining that her positive test was due to contamination of her sleep medication, melatonin.

A relieved Swiatek will next face American Emma Navarro, who defeated Russian Darya Kasatkina 6-4 5-7 7-5.