Canada's Denis Shapovalov is moving on at the U.S. Open after his compatriot Felix Auger-Aliassime was forced to retire in the third set of their first-round match on Monday.
The clash between the promising Canadian teenagers was cut short with Shapovalov leading 7-5, 5-7, 4-1.
Watch highlights from the all-Canadian clash:
Auger-Aliassime of Montreal, who was making his first appearance in the main draw of a Grand Slam, was attended to by medical staff during a changeover in the third set and said his heart was racing.
The 18-year-old attempted to return to play after a pause, but retired after looking out of sorts for the next three games.
Shapovalov of Richmond Hill, Ont., embraced a tearful Auger-Aliassime at centre court after the match ended.
Watch Shapovalov console Auger-Aliassime after his decision to retire:
Both struggle with their serves
Both teens struggled with the consistency of their service game. Shapovalov launched four aces, nine double faults got just 55 per cent of his first serves in. Auger-Aliassime, meanwhile, had three aces, nine double faults and landed 53 per cent of his first serves.
The 28th-seeded Shapovalov also fired 25 winners and had 48 unforced errors, while his Canadian counterpart had 10 and 45, respectively.
Shapovalov will face Andreas Seppi of Italy in the second round.
Shapovalov is 19, making him the youngest player in the ATP top 100. Auger-Aliassime just turned 18 on Aug. 8, making him youngest player in the ATP top 200. Their combined age made this the youngest U.S. Open men's match since 2006, when Novak Djokovic, 19, beat Donald Young, 17.
In other men's first-round action, Vancouver's Vasek Pospisil downed Lukas Lacko of Slovakia in straight sets 7-5, 6-3, 6-2.
Watch Pospisil close out Lacko:
Pospisil will face the winner of tonight's match between Rafael Nadal and David Ferrer.
Raonic advances to 2nd round
Canada's Milos Raonic advanced to the second round of the U.S. Open with a 7-6 (4), 6-4, 1-6, 6-3 victory over Argentine qualifier Carlos Berlocq on Monday.
Watch highlights of Raonic's first-round win:
The hard-serving star from Thornhill, Ont., fired 26 aces past Berlocq and won 91 per cent of his first service points.
It wasn't a clean win for Raonic, who committed 45 unforced errors compared to Berlocq's 11.
Canada's Milos Raonic returns a shot in his men's singles first-round match against Carlos Berlocq of Argentina on Monday. (Julian Finney/Getty Images)
Raonic, the 25th seed in New York, will next face France's Gilles Simon. Raonic owns a 4-1 advantage in the head-to-head series with Simon, including both meetings on hardcourts.
Raonic was originally scheduled to face Jared Donaldson in the first round before the American withdrew due to a knee injury.
