Fourth seed Daniil Medvedev cruised into the Australian Open quarter-finals with a straight-set victory over American Mackenzie McDonald.
The Russian saw off the world number 192 in one hour and 29 minutes, winning 6-4 6-2 6-3 on Margaret Court Arena.
"I want more all the time, but step by step, so this is amazing," said Medvedev, who has now won 18 consecutive matches.
He will face compatriot Andrey Rublev in the last eight at Melbourne Park.
Seventh seed Rublev was leading 6-2 7-6 (7-3) when Norwegian opponent Casper Ruud retired with an injury.
It means there are three Russian men in the quarter-finals of a Grand Slam for the first time in the Open era, with qualifier Aslan Karatsev also reaching the last eight.
No Russian male has won a Grand Slam since Marat Safin in Melbourne in 2005.