Kitzbühel - Defending champion Philipp Kohlschreiber of Germany and third-seeded Marcel Granollers of Spain both lost in straight sets in the second round of the Generali Open on Wednesday.
Kohlschreiber, who was seeded second, was upset by the 104th-ranked Karen Khachanov of Russia 6-4, 6-4, while 2013 champion Granollers was beaten by Adam Pavlasek of the Czech Republic 6-2, 6-4.
Khachanov plays Dusan Lajovic in the quarter-finals. The sixth-seeded Serb defeated Mischa Zverev of Germany 6-4, 6-4.
Pavlasek next takes on Nikoloz Basilashvili of Georgia, who beat Igor Sijsling of the Netherlands 6-4, 4-6, 6-2.
Also, fourth-seeded Paolo Lorenzi of Italy, eighth-seeded Jan-Lennard Struff of Germany and Gerald Melzer of Austria advanced to the quarter-finals.
Results from the third day of the ATP event in Kitzbuhel on Wednesday (x denotes seeding):
Jurgen Melzer (AUT) bt Dominic Thiem (AUT x1) 6-3, 7-5
Gerald Melzer (AUT) bt Daniel Gimeno (ESP) 6-3, 6-1
Paolo Lorenzi (ITA x4) bt Roberto Carballs (ESP) 6-2, 6-2
Jan-Lennard Struff (GER x8) bt Daniel Muoz (ESP) 7-5, 7-5
Nikoloz Basilashvili (GEO) bt Igor Sijsling (NED) 6-4, 4-6, 6-2
Adam Pavlsek (CZE) bt Marcel Granollers (ESP x3) 6-2, 6-4
Dusan Lajovic (SRB x6) bt Mischa Zverev (GER) 6-4, 6-4
Karen Khachanov (RUS) bt Philipp Kohlschreiber (GER x2) 6-4, 6-4