Felix Auger-Aliassime, a two-time US Open semi-finalist, used his experience to come through a potentially tricky tie against Alejandro Tabilo 6-3 7-5 6-1.
In theory, Chile’s Tablio should have been the fresher of the competitors, having spent about six hours less on court last week after being handed a walkover in round two.
Canada’s Auger-Aliassime started strongly, though, breaking at 3-1 before the remainder of the opening set stayed on serve.
Tabilo had never previously gone beyond the third round at a Slam but raised his level in the second.
The 28-year-old, who celebrates his birthday on Tuesday, played aggressively from the baseline and it almost paid dividends as he looked to break for 5-4.
But Auger-Aliassime raised his level to break for a 6-5 lead and served out the set to take full control.
Tabilo wilted in the third and was broken three times as his hopes of a first major quarter-final spot were ended.
“Since I was 12 or 13 it has always been a dream for me to get this far,” Auger-Aliassime said.
“I am a French-speaking guy – I can say I am very, very happy to get your support and I hope I will have your support until the end.”