Defending champion Jannik Sinner has moved into the quarterfinals at the Australian Open after beating Holger Rune during a match slowed down by medical timeouts for each player and a delay because the net got knocked loose.

Novak Djokovic was at the centre of another Australian Open row on Monday while Jannik Sinner needed medical attention in fierce heat to battle into the quarter-finals and Iga Swiatek won easily. But American teenage qualifier Learner Tien’s fairytale run is over after he suffered a thigh problem in a four-set defeat to Italy’s Lorenzo Sonego in Melbourne.

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.