Viktor Troicki, Roberto Bautista Agut advance at Sofia Open

SOFIA, Bulgaria -- Second-seeded Viktor Troicki reached the Sofia Open quarterfinals after defeating German qualifier Daniel Brands 6-4, 6-3 on Thursday.

Troicki advanced to his second quarterfinal in three tournaments this year.

"He has a very aggressive game, which I usually like to play against, and that's maybe why I played really well," Troicki said of Brands.

Top-seeded Roberto Bautista Agut of Spain also advanced after Filip Krajinovic of Serbia withdrew before their second-round match because of a right shoulder injury.

Bautista Agut, the top seed in an ATP event for the first time, will play eighth-seeded Adrian Mannarino of France in the quarterfinals. They are 2-2 in career matchups.

Also through was fourth-seeded Andreas Seppi of Italy, who beat Thiemo de Bakker of the Netherlands 6-2, 6-1, and will try to beat seventh-seeded Martin Klizan of Slovakia on Friday for a third straight time on tour.

In the final match of the day, fifth-seeded Philipp Kohlschreiber of Germany beat Damir Dzumhur of Bosnia-Herzegovina 6-1, 4-6, 6-3 in 90 minutes in the last single match of the day.