John Isner and Bernard Tomic claimed first-round wins at the Rogers Cup as Nick Kyrgios suffered a shock loss.

Isner and Tomic were joined as winners by Jack Sock and Grigor Dimitrov, while Kyrgios slumped to a defeat.

Kyrgios was stunned by teenage Canadian wildcard Denis Shapovalov, who won in three sets.


ISNER, TOMIC PROGRESS AS KYRGIOS LOSES

American Isner recovered from a slow start, firing down 15 aces in a 4-6 6-3 6-2 win over Dudi Sela.

On a warm day in Toronto, Tomic was also a winner, beating Alejandro Gonzalez 6-4 7-6 (7-1).

Tomic's Australian countryman Kyrgios, however, had no such luck, slumping to a 7-6 (7-2) 3-6 6-3 defeat to 17-year-old world number 370 Shapovalov.


KYRGIOS THE ONLY SEED TO FALL

Kyrgios, the 11th seed, was the only seeded player to depart.

The only other seed in action was Sock, who was far too good for fellow American Denis Kudla 6-2 6-2.


DIMITROV FIGHTS BACK, POLANSKY CRUISES

Dimitrov, who has endured a below-par year, fought his way past Yuchi Sugita 5-7 7-6 (7-5) 6-4.

The Bulgarian trailed 5-2 in the second-set tie-break before winning five straight points.

Canadian Peter Polansky lost no points on serve in the third set of his 4-6 6-3 6-0 win over Tim Smyczek.


KYRGIOS PAYS TRIBUTE TO SHAPOVALOV

Kyrgios was full of praise for Shapovalov, the Wimbledon junior champion, but was nursing an injury.

WAWRINKA, BERDYCH TAKE CENTRE STAGE

Swiss second seed Stan Wawrinka begins his campaign with a clash against Mikhail Youzhny. Tomas Berdych is set to be tested by talented Croatian Borna Coric.