The World No. 1, despite feeling unwell in sweltering conditions, kept up his title defense with a four-set triumph.

Defending champion Jannik Sinner moved into the Australian Open quarterfinals at Melbourne Park on Monday by eliminating the 13th-seeded Holger Rune 6-3, 3-6, 6-3, 6-2.

Jannik Sinner moved into the Australian Open quarterfinals Monday by eliminating Holger Rune in a match paused by medical timeouts and the net detaching from the court.

Jannik Sinner is through to the Australian Open quarterfinals after a drama-filled fourth-round win over Holger Rune. World No. 1 Sinner won in four sets, 6-3. 3-6, 6-3, 6-2, but this did not tell the story of a contest defined by illness.

Jannik Sinner, the world No 1 and defending champion, looked to be heading out of the Australian Open until he was rescued by a controversial medical time-out.