He joins 4th seed Daniil Medvedev in the last eight.
Rafa Nadal has booked his place in the quarter finals of the Australian Open.
The Spaniard, who's aiming for a record 21st Grand Slam title, beat Italy's Fabio Fognini 6-3 6-4 6-2 in their fourth round match.
Fourth seed Daniil Medvedev is also into the last eight in Melbourne after a straight sets win over Mackenzie McDonald.
Women's top seed Ashleigh Barty's in fourth round action later against American Shelby Rogers.
Fifth seed Elina Svitolina was beaten in three sets by Jessica Pegula.