Britain's Jack Draper and Dan Evans are through to the Canadian Open quarter-finals but Cameron Norrie was knocked out.
Draper, 20, led Gael Monfils 6-0 0-2 in their last-16 match when the Frenchman had to withdraw with a suspected ankle injury in Montreal.
Evans defeated American 10th seed Taylor Fritz 7-6 (9-7) 1-6 7-5.
British number one Norrie lost 6-3 6-4 to home favourite and sixth seed Felix Auger-Aliassime.
Wimbledon finalist Nick Kyrigos is also through to the last eight after defeating fellow Australian Alex de Minaur 6-2 6-3.
"Today was really hard mentally for me to go out here and play Alex," Kyrigos said.
"We're such good friends and he's been having such a good career so far and carrying the Australian flag for so long. It was just tough mentally. It's never easy to play a player like that, especially if they're Australian.
"I just got out here and got the job done. I played the way I had to play."
It is the first time that Draper has reached the quarter-finals of a Masters 1,000 tournament.
"I know what it's like to do an ankle," Draper said post-match. "I did one last year and rebounded. I hope Gael is all right. I wish him all the best for the rest of the season. I guess to be in the quarter-finals is nice for myself, but it's never how you want it to happen."
Draper, who upset third seed Stefanos Tsitsipas in the previous round, will face Spaniard Pablo Carreno Busta next.
Evans, who also beat Fritz in Washington last week, will play another American, Tommy Paul, in the last eight.
Draper and Evans would meet in the semi-finals if they both won their next matches.
In the women's tournament taking place in Toronto, world number one Iga Swiatek was beaten 6-4 3-6 7-5 by Brazilian Beatriz Haddad Maia.
Swiatek, who had a run of 37 straight wins halted in the third round at Wimbledon last month, said: "Next time maybe I'm going to be able to find, even though the conditions are going to be bad, more solutions and just play more solid. Because I did a lot of mistakes that I kind of don't accept."
American 10th seed Coco Gauff is also into the last eight after beating Belarusian world number six Aryna Sabalenka 7-5 4-6 7-6 (7-4).
Gauff will now play former world number one Simona Halep, who defeated Switzerland's Jil Teichmann 6-2 7-5.