Top-seeded Dominic Thiem and a returning Stan Wawrinka both won their quarterfinal matches at the St. Petersburg Open on Friday.
Thiem came through a tough encounter against Daniil Medvedev of Russia, managing 10 aces on his way to a 6-2, 3-6, 7-6 (2) victory. The French Open runner-up dominated from the off and broke Medvedev early on twice to take the opening set in just 30 minutes.
The Austrian will now face Roberto Bautista who won 7-6 (0), 6-3 against Marco Cecchinato.
In the other quarterfinals, the experienced Stan Wawrinka saw off the champion from last year at the St. Petersburg champion Damir Dzumhur, 6-3, 6-4. There were plenty of nerves from Wawrinka, who has had two operations on his knee, and he dropped his serve early in the opening set.
He recovered however and broke early in the second set before experiencing little trouble from then on.
The Swiss will now play Martin Klizan of Slovakia in the other semifinal.