Hamburg - Lukas Rosol has upset 2006 champion Tommy Robredo of Spain 7-5, 7-6 (6) on Thursday to reach the quarter-finals of the Hamburg Open.
The 42-ranked Czech saved seven break points while converting his one chance, and defeated the No. 3 seed in 1 hour 46 minutes.
Rosol, who lost in the final in Stuttgart against Roberto Bautista Agut on Sunday, awaits the winner between Philipp Kohlschreiber or 2011 champion Gilles Simon.
German wild card Tobias Kamke knocked out the fourth-seeded Alexandr Dolgopolov with a 7-5, 2-6, 7-5 victory in just over two hours.
Argentina's Leonardo Mayer beat Austria's Dominic Thiem 6-3, 6-2, Spain's Pablo Andujar defeated Dustin Brown of Germany 6-1, 6-2 and Dusan Lajovic was leading 3-1 when fellow Serbian Filip Krajinovic retired due to illness.
Results from the Hamburg ATP tournament on Thursday (x denotes seeding):
Second roundPablo Andjar (ESP) bt Dustin Brown (GER) 6-1, 6-2
Tobias Kamke (GER) bt Aleksandr Dolgopolov (UKR x4) 7-5, 2-6, 7-5
Lukas Rosol (CZE) bt Tommy Robredo (ESP x3) 7-5, 7-6 (8/6)
Leonardo Mayer (ARG) bt Dominic Thiem (AUT) 6-3, 6-2
Dusan Lajovic (SRB) bt Filip Krajinovic (SRB) 3-1 - retired