Dominic Thiem, 27, said it felt strange to be one of the oldest players left in the US Open after he stormed his way into the quarter-finals Monday.
The second seed bulldozed 20-year-old rising star Felix Auger-Aliassime of Canada 7-6 (7/4), 6-1, 6-1 in just 2hr 7min on Arthur Ashe court.
The Austrian won 74 percent of first serve points compared to just 60 percent for Auger-Aliassime.
The Canadian hit 51 unforced errors, with Thiem, the world number three, recording just 24.
Thiem is the highest-ranked player left in the tournament after world number one Novak Djokovic was sensationally disqualified for accidentally hitting a line judge after smashing a ball in frustration during his last-16 match on Sunday.
The 33-year-old's departure blew the tournament wide open and means it will produce a first-time Grand Slam winner in the men's competition this year.
With Roger Federer and Rafael Nadal absent, Thiem -- who is still searching for his Grand Slam title -- now finds himself in the unusual position of being considered a veteran.
"I'm probably one of the oldest players in the field, which is a bit surreal to me," said Thiem, who only turned 27 last week.
In fact, he is the second oldest in the last eight behind Pablo Carreno Busta, who is 29.
Thiem will play 21-year-old Australian Alex de Minaur, for a spot in the semi-finals.
De Minaur breezed past unseeded Canadian Vasek Pospisil 7-6 (8/6), 6-3, 6-2, in 2hr 17 min Monday.
Also in the quarters are 21-year-old Denis Shapovalov, 22-year-old Andrey Rublev and 23-year-old Borna Coric and Alex Zverev, also 23.
Tenth seed Rublev advanced on Monday after a four-set win over Italian sixth seed Matteo Berrettini, winning 4-6, 6-3, 6-3, 6-3.
The final spot in the round of eight will be taken by either 24-year-old Daniil Medvedev or 22-year-old Frances Tiafoe.
"It doesn't matter if the 'Big Three' are here or not. Everybody wants their hands on the trophy," said Thiem.