ISTANBUL (AP) Top-seeded Bernard Tomic was knocked out of the Istanbul Open, losing to unseeded Diego Schwartzman of Argentina 6-2, 6-2 on Thursday.
As the top seed, Tomic also lost his opening match a week ago at the Nastase Tiriac Trophy in Bucharest.
''I'm playing well on these courts, which are slow,'' Schwartzman said. ''I tried to be focused today and I think I played a great match.''
In the quarterfinals, he faces Damir Dzumhur of Bosnia and Herzegovina, who defeated Illya Marchenko of Ukriane 6-3, 5-7, 6-3.
Third-seeded Ivo Karlovic hit 13 aces to advance past Dusan Lajovic of Serbia 7-6 (11), 7-6 (7), recording his 300th career victory, and will play fifth-seeded Marcel Granollers of Spain, who defeated Hyeon Chung of South Korea 6-3, 6-4.