In a match disrupted by medical timeouts and a broken net, both Sinner and Rune seemed to struggle with the 32C heat on Rod Laver Arena.

Sinner, towards the end of the second set and into the third, was visibly shaking during the changeovers as he wrapped ice towels around his neck.

But the world number one prevailed to win 6-3 3-6 6-3 6-2 against the Dane.

“I was not feeling really well,” said Sinner.

Speaking on court after his win, the 23-year-old said: “I knew in my mind even before the match I would struggle today.

“This morning was a very strange morning because I didn’t even warm up today, trying to go on court as fit as I could.”

He will face either Australian eighth seed Alex de Minaur or American Alex Michelsen in the last eight.

Elsewhere, Italy’s Lorenzo Sonego beat American qualifier Learner Tien 6-3 6-2 3-6 6-1 to reach his first Grand Slam quarter-final.

Sonego will play 21st seed Ben Shelton next after the American’s fourth-round opponent, Frenchman Gael Monfils, retired with a back issue while trailing 7-6 (7-3) 6-7 (3-7) 7-6 (7-2) 1-0.

After two gruelling service games in the third set, Sinner’s physical troubles came to the fore and he called for the trainer after saving a break point to go 3-2 up.

He received treatment off-court and returned after more than 11 minutes, but it was Rune who faltered and allowed Sinner to break for a 5-3 lead.

The 13th seed needed a medical timeout of his own for an apparent knee injury before Sinner raced to a love hold to wrap up the set.

There was a further 21-minute pause in play at the start of the fourth as the pair returned to the locker room when the net’s anchoring pin in the middle came loose.

The interval seemed to benefit Sinner, who steamrolled his way to a 5-2 lead and served out the victory after three hours and 13 minutes.

“It was very tough. I knew in my mind he had some very long matches so I tried to stay there mentally,” Sinner added.

“Today the support meant so much to me, I really needed you guys today. It’s 90% yours and 10% I try to make you happy.”

Sinner is on a 17-match winning streak, with his last defeat coming in the Beijing Open final against Carlos Alcaraz in October.

There is potential for an all-Italian semi-final tie after unseeded Sonego’s win over 19-year-old Tien in four sets.

Tien was bidding to become the youngest man to reach the last eight in Melbourne since a 17-year-old Goran Ivanisevic in 1989 but, with strapping on his right thigh, struggled with injury.

“Today was so tough, I’m so sad that he had a problem. It’s not the right way to win, but I’m so happy to reach the quarter-finals,” said 29-year-old Sonego.

The 24-time Grand Slam champion is 16 years Rune’s senior but doesn’t underestimate the challenge the Dane will pose when they close proceedings on Centre Court.

“Rune’s a spectacular player, no doubt. He loves the big stage, loves playing on grass. I think he’s a very, very tricky opponent,” said second seed Djokovic.

The 37-year-old is going for an eighth Wimbledon title and record 25th Grand Slam overall.

“It’s going to take my best tennis to win,” he added.

“I actually get along very well with [Rune]. He’s a very nice guy, always has been to me and to my team, and vice versa.”

The pair have met five times previously, with Serb Djokovic winning on three occasions, including the two most recent, on hard courts in 2023.

“I always try to be available to him for any practice or advice or guidance or anything like that,” said Djokovic.

“I think we have quite similar styles of tennis. But when it comes to playing on the court and competing, obviously we both have that fire. I’m sure that on Monday, we’ll see a lot of fireworks on the court.”

Following knee surgery just weeks before arriving at SW19, Djokovic is yet to win a match in straight sets at the All England Club but Rune said he still expects a “tough battle”.

“I’m expecting nothing but a great level from him. I know he did his surgery, but honestly, I practised with him in the first week, and I saw him playing a little bit,” said the 15th seed.

“He seems like he’s playing very well, feeling confident.”

Elsewhere on day eight of the Championships, American 13th seed Taylor Fritz will take on German fifth seed Alexander Zverev on Centre Court while Australian ninth seed Alex de Minaur opens play on Court One against France’s Arthur Fils.

Women’s singles draw wide open after shock exits

Kazakh fourth seed Elena Rybakina will open play on Centre Court against 17th seed Anna Kalinskaya with her sights fixed on the quarter-finals after a string of shock exits in the women’s draw.

After second seed Coco Gauff’s straight-set defeat by fellow American Emma Navarro on Sunday, 2022 Wimbledon champion Rybakina is the last of the top five seeds still in the competition.

Only two of the top 10 remain, with Italian seventh seed Jasmine Paolini through to the last eight.

Kazakhstan’s Yulia Putintseva sent number one seed Iga Swiatek out on Saturday and her reward is an outing on Court One against Latvian 13th seed Jelena Ostapenko in round four.

American 11th seed Danielle Collins takes on Czech 31st seed Barbora Krejcikova in the final match scheduled for Court One.

On court two, Ukraine’s Elina Svitolina, seeded 21st, will look to avoid slipping up against China’s Wang Xinyu.