Canada’s Vasek Pospisil couldn’t convert on four set points in the first set en route to a 7-6 (6), 6-3, 6-2 loss against No. 21 seed Alex de Minaur of Australia in the fourth round of the U.S. Open on Monday.
The Vancouver player, ranked 94th, seemed firmly in control of the tiebreak before losing six straight points to drop the set.
De Minaur then broke Pospisil twice in the second set and rolled to victory, sending the 21 year old to his first Grand Slam quarterfinal.
Pospisil was one of a record three Canadian men to reach the round of 16 at the U.S. Open.
WATCH | Pospisil eliminated in 4th round at U.S. Open:
No. 12 seed Denis Shapovalov of Richmond Hill, Ont., beat No. 7 seed David Goffin in four sets on Sunday night to set up a quarter-final 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 quarter-finals. Previously, Canadian men were 0-12 in the round of 16.
No. 15 seed Felix Auger-Aliassime of Montreal was scheduled to face No. 2 seed Dominic Thiem of Austria in a fourth-round match later Monday.
The 30-year-old 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.
De Minaur, who beat No. 11 seed Karen Khachanov of Russia on Saturday, and Pospisil both came back from 2-1 set deficits to prevail in the third round.
It has been a promising last 12 months for Pospisil, who missed the first half of last year after back surgery. He helped Canada reach the Davis Cup final late last year and has an 11-6 record this year, including a runner-up showing at a tournament in Montpellier, France.
Pospisil is projected to move up to No. 72 in the rankings next week. He reached a career high of No. 25 in 2014 when Pospisil reached his first and only Grand Slam quarterfinal at Wimbledon.
Meanwhile, 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 quarter-final on Monday.
Shapovalov and partner Rohan Bopanna of India were scheduled to play a men’s doubles quarterfinal against Jean-Julien Rojer of the Netherlands and Horia Tecau of Romania later Monday.