Carlos Alcaraz goes on to face either American 27th seed Sebastian Korda or South Korea's Kwon Soon-woo for a place in the last 16.
Karen Khachanov had already won the first two sets 7-6, 6-3 and had a 3-0 lead over USA's Sebastian Korda in the third set.
Korda, whose father Petr won the title in 1998, had produced one of the performances of his career to upset two-time Australian Open finalist Daniil Medvedev in the third round.