Felix Auger-Aliassime's Rogers Cup run is over.
No. 6 seed Karen Khachanov of Russia defeated the Montreal teenager 6-7 (7), 7-5, 6-3 in third-round action at a windy and raucous IGA Stadium on Thursday afternoon.
A rising star celebrating his 19th birthday, Auger-Aliassime pushed ahead early, but was undone by 12 double faults and a series of mistakes at key times.
Victorious in just six total outings prior to 2019, the world's 21st-ranked player and last remaining Canadian in the men's bracket has made three finals since February, but is still looking for his first title.
Khachanov, meanwhile, now turns his attention to the quarterfinals.
In front of a decidedly partisan gathering Thursday, Auger-Aliassime won a sloppy first set in gusty conditions that saw both players broken twice and commit a number of unforced errors.
Tied 7-7 in the tiebreak, Khachanov sent a shot into the net on serve and then fired another ball over the second deck and out of the venue in frustration after dropping two set points up 6-4, leading to boos.
Auger-Aliassime sealed the set on his next serve, much to the delight of the adoring crowd.
After three breaks apiece in the second set, Khachanov broke the 19-year-old Canadian for a fourth time to secure a 7-5 decision that evened the match on centre court.
Khachanov broke Auger-Aliassime again to go up 3-1 in the third set.
The hometown favourite battled back to make it 4-2 as fans chanted his name, but Khachanov held serve despite going down 0-30 in the final game to seal the match in two hours 50 minutes.
After the match, the crowd sang "Happy Birthday" to Auger-Aliassime, while a video featuring fellow pros also passing on their greetings played on the big screens.
Auger-Aliassime, who started the year ranked 108th, advanced to Thursday's round of 16 after victories in all-Canadian matchups with Vancouver's Vasek Pospisil and Milos Raonic of Thornhill, Ont.
Pospisil gave the teen all he could handle in the first round before Auger-Aliassime advanced following a third-set tiebreak at the US$5.7-million ATP Tour Masters 1000 series event.
Raonic, the top-ranked Canadian at No. 19, was then forced to retire from their second-round match with things tied at one set apiece because of a back injury on Wednesday night. Raonic, 28, also withdrew from a scheduled semifinal with Auger-Aliassime in Stuttgart in June.
The 23-year-old Khachanov, ranked a career-high No. 8, advanced to the third round with a victory over Stan Wawrinka.
Top-seed and world No. 2 Rafael Nadal, a four-time Rogers Cup champion, was set to take on Argentina's Guido Pella in Thursday's evening session.
The 33-year-old Spaniard won last year's tournament in Toronto, site of the women's bracket in 2019.
In other action, second-seed Dominic Thiem advanced to the quarterfinals with a 7-6 (7), 6-4 win over Croatia's Marin Cilic.
Thiem fired 11 aces and saved all nine break points he faced. He also broke Cilic once in four opportunities.
The 25-year-old Thiem -- ranked No. 4 in the world behind Novak Djokovic, Nadal and Roger Federer -- was coming off a victory on clay at the Generali Open in his native Austria. He's won three tournaments in 2019, including two on clay, but hadn't competed in a hardcourt event since March before this week.
Cilic, the 2014 winner at the U.S. Open, advanced to the quarters at last year's Rogers Cup before falling to Nadal.
Meanwhile, No. 3 seed Alexander Zverev of Germany beat Georgia's Nikoloz Basilashvili 7-5, 5-7, 7-6 (5), and No. 8 seed Daniil Medvedev of Russia also booked a spot into the fourth round with a 6-3, 6-3 decision over Chile's Cristian Garin.