Top seed Dominic Thiem is through to the quarterfinals of the St Petersburg Open after getting the better of Jan-Lennard Struff in straight sets.
The world no. 8 ran into a little bit of difficulty in the first set, requiring a tiebreak to edge ahead of his German opponent, but eventually went on to take the match 7-6 (4), 6-4.
Defending champion Damir Dzumhur also reached the quarterfinals by beating Guido Pella 6-4, 6-4.
Dzumhur landed 70 percent of his first serves on his way to a win which set up a quarterfinal with Stan Wawrinka.
Also, 19-year-old Canadian Denis Shapovalov defeated Italian player Matteo Berrettini 7-6 (6), 4-6, 6-0 and lined up a quarterfinal against Martin Klizan.
The eighth-seeded Daniil Medvedev of Russia prevailed against Mikhail Kukushkin 6-3, 6-4 in their second-round match.