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.

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 bizarre 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.