NEW YORK — Montreal's Felix Auger-Aliassime saw his run at the U.S. Open end with a tough loss in straight sets Monday, but he hopes his performance on one of tennis' biggest stages can help inspire other young Canadians.

The 20 year old battled No. 2 seed Dominic Thiem of Austria to a tiebreak in the first set of the round of 16 match on Monday. But he struggled in the second and third sets, committing 51 unforced errors in the 7-6(4), 6-1, 6-1 loss.

"I was able to come back well in the first, gave myself a chance to maybe win the first and then, you know, I missed at the important moments," Auger-Aliassime told reporters after the match.

Thiem broke Auger-Aliassime five times in three sets.

"I feel like that really gave him confidence and hurt me more than it did anything," the Canadian said. "Then from that, it was just tough. He was playing good, heavy, and I was just playing worse and worse."

Auger-Aliassime came into the tournament as the No. 15 seed and is the first player born in the 2000s to make the fourth round of a Grand Slam.

He beat three-time Grand Slam champion Andy Murray in the second round.

There are a lot of positives to take from the first three matches, Auger-Aliassime said.

"I will try to see what I can learn and see what I can improve from this loss in particular, and I think I'll focus on the good things that also happened this week and go from there," he said.

Canadians have performed well at this year's U.S. Open. Auger-Aliassime was one of a record three Canadian men to reach the round of 16.

"I hope it inspires kids from our country, from our respective provinces and cities, you know, just to show them that it's possible," he said. "We were showing that we're a country that can be dominant in this sport. We have already shown with the finals last year in Davis Cup, but I think now we show that we can go deep in these tournaments."

Vancouver's Vasek Pospisil also made the round of 16 before he was beaten in straight sets by No. 21 seed Alex de Minaur of Australia on Monday.

Pospisil, ranked 94th, said he was battling quadricep and abdominal strains when he failed to convert on four set points in the first set en route to a 7-6 (6), 6-3, 6-2 loss.

"I just tried to manage it but it impacted my serve the most out of all my strokes, so that was not ideal," he told reporters after the match. "But it is what it is ... It's a Grand Slam so it's very physical and at some point your body's going to take a beating and I think it definitely affected me a little bit today."

De Minaur broke Pospisil twice in the second set and rolled to victory, sending the 21 year old to his first Grand Slam quarterfinal.

De Minaur's speed is difficult to keep up with, Pospisil said.

"What's most impressive is that he never breaths," he said with a laugh. "He runs side to side and he's never out of breath. He defies the laws of biology, I guess. It's pretty impressive but he's definitely a freak of nature."

Pospisil upset No. 25 seed Milos Raonic of Thornhill, Ont., and No. 8 seed Roberto Bautista Agut of Spain before his surprise run came to an end against de Minaur.

No. 12 seed Denis Shapovalov of Richmond Hill, Ont., remains in the tournament. He beat No. 7 seed David Goffin in four sets on Sunday night to set up a quarterfinal match against No. 20 seed Pablo Carreno Busta of Spain on Tuesday.

Carreno Busta advanced when the top-ranked Novak Djokovic was kicked out of their match for accidentally hitting a line judge in the throat with a tennis ball after dropping a game.

Shapovalov is the first Canadian man in history to reach the U.S. Open quarterfinals. Previously, Canadian men were 0-12 in the round of 16.

Earlier on Monday, Ottawa's Gabriela Dabrowski and American partner Alison Riske lost 6-4, 6-2 to Americans Asia Muhammad and Taylor Townsend in a women's doubles quarterfinal on Monday.

In men's doubles quartefinal action, Shapovalov and partner Rohan Bopanna of India lost 7-5, 7-5 to Jean-Julien Rojer of the Netherlands and Horia Tecau of Romania on Monday.

This report by The Canadian Press was first published Sept. 7, 2020.