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.

Sinner was joined in the quarter-finals by countryman Lorenzo Sonego, who is through to this stage at a grand slam for the first time after ending the run of 19-year-old American Learner Tien with a 6-3 6-2 3-6 6-1 victory.