Daniil Medvedev firmed as an Australian Open title contender when he brushed aside Mackenzie McDonald 6-4 6-2 6-3 to reach the quarter-finals for the first time and extend his winning streak to 18 matches on Monday.
The fourth seeded Russian won his first career five-set match in the third round but there was no need for a prolonged spell in the sun on Monday and he saw off McDonald in less than 90 minutes on Margaret Court Arena.
"It was a great match, I served well, I played well," said Medvedev.
"I was feeling great. I finished it in 1.30, which is important at this stage of the tournament. I managed to take all my chances today I think."
Medvedev's winning streak includes victories over Novak Djokovic, Rafa Nadal, Dominic Thiem and Alexander Zverev, and titles at the ATP Finals, Paris Masters and most recently the ATP Cup as mainstay of the Russian team.
World No.192 McDonald had some luck going to the net but could not match the power of Medvedev's serve or the intensity the Russian brought to bear on big points.
Medvedev converted six of the seven break points he carved out, the last to win the match and set up a last-eight clash with compatriot Andrey Rublev or Norwegian Casper Ruud.
"I'll be for Andrey because if he wins, it's going to be at least one Russian in the semi-final," Medvedev added.
"Maybe two with Aslan (Karatsev) playing in the other side of the draw."
Qualifier Karatsev will play Grigor Dimitrov for a place in the last four on Tuesday.
Italian ninth seed Matteo Berrettini withdrew from his fourth-round match against Greek fifth seed Stefanos Tsitsipas due to an abdominal strain.
Tsitsipas will face Spanish second seed Rafa Nadal, who is chasing a record 21st Grand Slam title, in the quarter-finals.
Nadal sealed a dominant 6-3 6-4 6-2 win over Italian 16th seed Fabio Fognini to reach the quarter-finals for the 13th time.
Seventh seed Andrey Rublev advanced after his opponent Casper Ruud retired while trailing 6-2 7-6(3).