MELBOURNE, Jan. 24 (Xinhua) -- Wang Xinyu ensured China will be represented in the fourth round of the Australian Open singles draw after a statement win, while title contenders Jannik Sinner and Novak Djokovic overcame injury concerns amid oppressive Melbourne weather on Saturday.

Day seven started an hour earlier than usual due to stifling heat. Play eventually needed to be suspended across Melbourne Park in the early afternoon as temperatures soared to 40 degrees Celsius.

Wang's 7-5, 6-4 upset of 13th seed Linda Noskova was disrupted for several hours after being halted at 2-2 in the first set.

But she remained unaffected and continued her aggressive form in the tournament to book a fourth round match with American fourth seed Amanda Anisimova.

"It's amazing. I feel like I have so much support here. It was tough but I'm really happy to win," Wang said.

Wang, the world No.46, is China's highest-ranked player in Melbourne after Zheng Qinwen, a former Australian Open finalist, withdrew ahead of the tournament.

She has lived up to top billing on the back of reaching her second career final with a runner-up finish to Elina Svitolina in Auckland.

The women's draw was headlined by world No.2 Iga Swiatek overcoming a patchy performance to beat 31st seed Anna Kalinskaya 6-1, 1-6,  6-1 in one hour and 44 minutes.

The six-time grand slam champion booked a clash with Australian qualifier Maddison Inglis, who progressed after four-time major winner Naomi Osaka withdrew from the tournament due to injury.

Defending champion Madison Keys had a comfortable 6-3, 6-3 win over former world number one Karolina Pliskova.

"I need to trust in my game and myself," said Keys after she booked a clash with American compatriot Jessica Pegula, who swept aside unseeded Russian Oksana Selekhmeteva 6-3, 6-2

"Nice to be first out on court and not a super long match and didn't need to kill myself in the heat today," Pegula said.

Former Wimbledon champion Elena Rybakina also made it through.

In the men's, Sinner overcame full body cramps to beat Eliot Spizzirri 4-6, 6-3, 6-4, 6-4 in three hours and 45 minutes.

As temperatures soared at Rod Laver Arena, the four-time grand slam champion needed medical attention early in the third set.

He benefited from a suspension due to the closure of the retractable roof as the extreme heat reached an unbearable level.

"He played really, really well. I struggled physically today and I got lucky with the heat rule. Very happy with my performance," said Sinner, who will play compatriot Luciano Darderi in the last 16.

Djokovic showed no ill-effects after tumbling to the court in a nasty fall as he clinched a record 400th grand slam win after downing Botic van de Zandschulp 6-3, 6-4, 7-6 (4) in two hours and 44 minutes.

The 24-time grand slam champion fell awkwardly early in the third set and he subsequently had his right ankle taped up.

"Really good," Djokovic said of his condition. "I'm not getting ahead of myself and I'm still hanging in there."

The Serb was also fortunate after almost hitting a ball kid while smashing the ball away, which could have led to a possible disqualification as had happened to him in similar circumstances at the 2020 US Open.

The 38-year-old will next face 16th seed Jakub Mensik.

Fifth seed Lorenzo Musetti edged a five-set thriller over Tomas Machac in a marathon match lasting four hours and 27 minutes, while eighth-seeded Ben Shelton also made it through.

American ninth seed Taylor Fritz beat 40-year-old Stan Wawrinka, who played his final match at the tournament where he won his first grand slam title in 2014.

In the women's doubles, China's Guo Hanyu partnered with France's Kristina Mladenovic to beat Anastasia Pavlyuchenkova and Clara Tauson in three sets.

Round four action starts on Sunday and will be headlined by top seeds Aryna Sabalenka and Carlos Alcaraz, while title contenders Coco Gauff and Alexander Zverev will also be stepping up their campaigns.  ■