Australian Open: Sinner toughs it out through illness to reach last eight

Melbourne: Defending champion Jannik Sinner overcame debilitating illness as well as Dane Holger Rune to reach the quarter-finals of the Australian Open for the third time with a 6-3 3-6 6-3 6-2 victory on Monday.

The world number one had looked like continuing his serene progress through the draw when he wrapped up the opening set after 33 minutes on the back of two breaks of serve.

The 23-year-old started to struggle physically early in the second set, however, and appeared even weaker after stretching in vain for one return.

"I don't want to talk so much about how I felt today. I was not feeling really well," Sinner told reporters.

"I think we saw that today, I was struggling physically. Came here as late as possible. I knew that it was going to be very, very difficult today, playing against a tough opponent but also playing against myself a little bit."

Rune was not going to look a gift horse in the mouth and moved his opponent around the court as much as possible. The 13th seed converted his first break point of the match when Sinner double-faulted and served out to clinch the second set.

Sinner, his hand shaking as he mopped his face with a towel, went to the locker room before the third set and fended off two break points in the third game, the second after a breathtaking 37-shot point which he won with a crosscourt winner.

'A bit dizzy'

The Italian slumped over his racket as the crowd gave the players a huge ovation and a couple of games later called for a doctor and went off court for an 11-minute medical timeout.

"I think we saw that I was not feeling well ... I was a bit dizzy at times," he said. "I don't want to go in details."

Rune, who played five, four and five sets in his first three matches, said he was also being stretched to his limits physically in the stifling Melbourne heat.

"It was really, really tough," said Rune. "I mean, I was almost dying, also. It was really a struggle. I could see he was also struggling."

Sinner was now moving more freely as the medicine he had been given kicked in and broke for 5-3 before serving out to claim the third set.

It was now Rune's turn for medical treatment and a trip to the locker room, while a 20-minute delay while the net anchor was fixed allowed for more recovery time.

"It was very helpful today," said Sinner. "Obviously nobody was expecting this kind of thing. It helped me. It was big, big luck to me today."

Sinner pounced to break for 2-1 in the fourth set on the back of three Rune errors and, with his serve back at full power, his 18th successive win at tour level looked assured.

A 54th unforced error from Rune secured Sinner's passage to the last eight of a Grand Slam for a 10th time, equalling the Italian record set by Nicky Pietrangeli in the 1950s and 1960s.

"I tried to handle the situation on the court as good as I could, which I think today I handled as well as possible," said Sinner. "Happy to be in the next round."

Sinner will next face either local hopeful Alex de Minaur or American young gun Alex Michelsen, who he has played a combined 11 times winning them all.