ST. PETERSBURG, Russia — Canada's Denis Shapovalov is out of the St. Petersburg Open.

The unseeded Martin Klizan of Slovakia rallied to beat the No. 7-seeded Shapovalov 3-6, 7-5, 6-3 in a quarterfinal on Friday.

The 19-year-old Shapovalov, of Richmond Hill, Ont., is ranked 34th in the world, while Klizan is 65th.

Meanwhile, top-seeded Dominic Thiem and fit-again Stan Wawrinka won their quarterfinal matches.

Austrian player Thiem came through a tough encounter against Daniil Medvedev of Russia, firing 10 aces on his way to a 6-2, 3-6, 7-6 (2) victory.

His reward is a semifinal with Roberto Bautista Agut of Spain, who won 7-6 (0), 6-3 against Marco Cecchinato.

Experienced Swiss Wawrinka, aiming for his first title since sustaining a severe knee injury last year, next plays Klizan after beating last year's St. Petersburg champion Damir Dzumhur 6-3, 6-4.

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