In the Australian Open Round of 16 on Sunday, No. 1-ranked Jannik Sinner takes on No. 13 Holger Vitus Nodskov Rune.Sinner enters the Round of 16 after his three-set win on Saturday over Marcos

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

Holger Rune didn't have anything against Jannik Sinner taking a medical timeout but noted that a lengthy break ruined his rhythm. After the world No. 1 started to physically struggle late in the second set of their Australian Open round-of-16 match - the Italian's hands were shaking and his movement was impacted - the Dane won that set and also had the upper hand early in the third set.