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.

First came the medical timeouts, one each for Jannik Sinner and Holger Rune with the temperature above 90 degrees Fahrenheit (32 Celsius) at the Australian Open. Then came the unusual sight of a 20-minute delay because the net at Rod Laver Arena detached from the court after being hit by a big Sinner serve.

In the quarterfinals, Sinner will face No. 8 Alex de Minaur of Australia, who ousted American Alex Michelsen 6-0, 7-6 (5), 6-3. It will be the first quarterfinals appearance for de Minaur in his home country's Grand Slam, and he became just the third Aussie man to reach the round in 20 years.

The 23-year-old Italian’s next opponent in Australia will be No. 13 Holger Rune, who beat Miomir Kecmanovic 6-7 (5), 6-3, 4-6, 6-4, 6-4.

MELBOURNE – If someone is required to dismantle a nation’s hopes, then Jannik Sinner is a fine choice. He will do it without fuss. He will not beat his chest, prance in victory or even grunt. He will simply not miss. He will bring cold calculation, a Gatling-gun forehand, a face that tells you nothing and puncture your challenge.

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

The defending champion moved into the quarterfinals at Melbourne Park on Monday by eliminating the 13th-seeded Rune 6-3, 3-6, 6-3, 6-2.

Jannik Sinner has revealed that he felt unwell ahead of his win over Holger Rune at the Australian Open, and is relieved to be through to the quarter-finals.