Weeks removed from winning the junior championship at Wimbledon, Canada's Denis Shapovalov scored his biggest career ATP Tour win Monday.
The 17-year-old upset 11th-seeded Australian Nick Kyrgios 7-6 (2), 3-6, 6-3 in the first round of the Rogers Cup at Toronto.
"I love playing on a big stage. I love impressing people," Shapovalov said. "It was very fun for me."
Kyrgios said of his opponent, "He's coming off of one of the best results of his career. He has a great future. I'm really looking forward to seeing how he's going to progress. ... He's a top player."
The other seeded players in action won their matches. No. 9 John Isner topped Israel's Dudi Sela 4-6, 6-3, 6-2. Twelfth-seeded Bernard Tomic of Australia eliminated Colombian qualifier Alejandro Gonzalez 6-4, 7-6 (1), while 16th-seeded Jack Sock topped Denis Kudla 6-2, 6-2 in an all-U.S. matchup.
The first round continues Tuesday, when two second-round matches are scheduled: second-seeded Stan Wawrinka of Switzerland against Mikhail Youzhny of Russia, and fifth-seeded Tomas Berdych of the Czech Republic against Borna Coric of Croatia.
--The only two seeded women in action Monday advanced in the first round of the Rogers Cup at Montreal.
Twelfth-seeded Petra Kvitova of the Czech Republic rolled past Polish qualifier Magda Linette 6-1, 6-2, while 13th-seeded Samanatha Stosur of Australia defeated Great Britain's Heather Watson 7-5, 6-3.
Johanna Konta, fresh off her first career tournament championship Sunday in Stanford, Calif., opens Rogers Cup play Tuesday against American Shelby Rogers. Konta is up to a career-high No. 14 ranking after her three-set victory over Venus Williams in the Bank of the West Classic final.