Jannik Sinner struggles past Holger Rune to reach Australian Open quarterfinals

It was not exactly a case of ‘Mondayitis’, but Jannik Sinner didn’t quite feel right when he woke up on the morning of his Australian Open fourth-round match against Holger Rune.

“I was not feeling really well,” Sinner told reporters after his four-set victory over Rune on Rod Laver Arena.