After a walkover and an in-match retirement, 10-time Australian Open winner Novak Djokovic will meet two-time defending champion Jannik Sinner in the semifinals.

Djokovic dropped the first two sets of his quarterfinal 6-4, 6-3 Wednesday to fifth-seeded Lorenzo Musetti but was up a break in the third when the 23-year-old Italian retired with an injured right leg.