Jannik Sinner recovers mid-match to fend off Holger Rune challenge

World no. 1 Jannik Sinner has survived a mid-match health scare to keep his title defence alive at Melbourne Park.

Jannik Sinner has played down an illness which left him “dizzy” and seeking treatment as his Australian Open title defence came under significant threat on Monday.

The world No. 1 had to withstand the Melbourne heat and a fierce challenge from 13th seed Holger Rune to advance to the quarterfinals with a 6-3, 3-6, 6-3, 6-2 win at Rod Laver Arena.

Sinner said he had no injury concerns but had moved awkwardly between points due to an illness, which he was reluctant to share the details of after a medical intervention helped him regain control of the clash midway through the third set.

“I was not feeling really well. I think we saw that today I was struggling physically. I came (to Melbourne Park) as late as possible (on Monday morning),” Sinner said.

“I knew it was going to very difficult today, playing against a tough opponent but also playing against myself a little bit.

“I think today I handled it as well as possible.”

Jannik Sinner struggles with the heat during his fourth-round win over 13th seed Holger Rune. Picture: Mark Stewart

Sinner left the court for a medical time-out lasting more than 10 minutes after he spoke to a doctor at 3-2 in the second set, with his right hand noticeably shaking as he was assessed courtside.

The Italian was closer to his best when he returned, and said he had received medication which had left him feeling better as he praised the Open as an “awesome tournament” with “great organisation”.

“I felt slightly better after I went back on court – I felt like (my) face looked a little bit better, the colour was a little bit back,” he said.

“Every player struggles a little bit (in the heat) … when you’re not there health-wise where you want to be, it’s even more difficult.”

Play was halted for more than 20 minutes early in the fourth set after a wayward Sinner serve struck the net and broke the part attached to a metal brace on the surface of the court.

Officials scramble to address the broken net which caused a 20-minute delay in play. Pioture: Hannah Peters / Getty Images

As officials scrambled to fix the problem, the umpire directed both players to move indoors out of the sun, which Sinner said had given him crucial time to recover.

“I was a bit dizzy at times, I don’t want to go into details now … I think it was also with the pressure and everything, it wasn’t easy, the sun came out at that point, it was more humid,” he said.

“(The broken net delay) helped me – I was lucky today at this point, 20 minutes off court … putting some cold water (on) my head. It was very helpful and a big, big luck to me today.”

Sinner took an early break to skip away to a 6-3 first set victory in 33 minutes, but he moved noticeably slowly between points and at times looked unsteady on his feet.

The 23-year-old still managed to bring the crowd to its feet with roars of appreciation after winning a phenomenal rally with an emphatic overhead smash to save a break point early in the second set.

Rune decided to go for broke and sent Sinner scurrying with a series of lusty backhand blows, and the physical demands clearly took a toll on the champion.

Danish star Holger Rune appeared on course to win when Sinner took the medical time-out in the third set. Picture: Mark Stewart

The 21-year-old Danish star had looked on a mission to reach his first quarterfinal at Melbourne Park, but whether from injury or the added pressure of being presented with a chance to down the world No. 1, he crumbled in his next two service games before seeking treatment on his knee.

Rune veered away from his strategy of lashing attempted winners as he played more slices and drop shots, which were executed poorly and allowed the Italian back into the match.

Sinner looked a class above when they resumed hostilities, making only four unforced errors to Rune’s 10 in the fourth set as he secured his place in the final eight.

Rune could only pitch his racquet against the court in frustration as he reflected on how he had let the match slip during a change of ends midway through the fourth.