Australian Open: Jannik Sinner battles health issue in win over Holger Rune

In searing conditions at Melbourne Park, the pair slugged it out early on and shared the opening two sets, but Sinner required a lengthy medical timeout midway through the third set.

Both the physio and doctor were on court and, after some initial checks, the Italian went to the locker room for further treatment with the timeout lasting more than 10 minutes.

The defending Australian Open champion was eventually given the all-clear to continue playing and broke the Rune serve in game eight before running away with the match to secure a 6-3, 3-6, 6-3, 6-2 victory.

But of concern for the Sinner - whose hand also shook uncontrollably at one stage and needed an ice towel to cool himself down - will be his health for the next match as he revealed he had problems before making his way to Rod Laver Arena in the morning.

"I knew in my mind that he had also had some very long matches before this. I tried to stay there mentally," the two-time Grand Slam winner stated.

"I just tried to stay connected with my service game and return game, and see what happened."

He added: "This morning was a strange morning, because I didn't even warm up today. I was trying to go on court as fit as I could be. I knew in my mind before the match that I would struggle. Game-wise, I played well, I served very well.

"There were quality shots that gave me the confidence to fight on, and of course, the time off the court, the doctor and I talked a little bit."

Sinner will face local hope Alex de Minuar for a place in the semi-final with the Australian known for his speed around the court, which could trouble the world No 1.

The Italian appeared to be hobbling during the match as well, but confirmed he doesn't have any injuries as it's just a "health issue" although he will be hopeful it was just a one-off.

"I didn't feel too good. It was hard for me physically, we all saw it. I came here as late as I could. I knew it would be very difficult, playing against a great rival, but also against myself. I tried to handle the situation on the court as best as possible. I'm happy to be in the next round.

"I had already spoken to the doctor before I went on court, I had a little check-up. It helped me, I felt better when I came back to the match. My face looked a little better, I got some colour back.

"These are very tough conditions. We all suffer a bit. There's nothing wrong with my leg. When I'm not feeling well, I usually walk on my left foot, but I don't have any injuries. It's just a health issue." 

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