Seeded players Viktor Troicki of Serbia and Marcos Baghdatis of Cyprus lost in the second round of the Nastase Tiriac Trophy on Thursday.
Fourth-seeded Troicki was defeated by Matthias Bachinger of Germany 6-3, 4-6, 7-6 (2), while fifth-seeded Baghdatis lost to Fabio Fognini of Italy 7-5, 7-6 (4).
In an all-Italian quarterfinal, Fognini will play against sixth-seeded Andreas Seppi, who beat Cedrik-Marcel Stebe of Germany 6-2, 6-3.
Top-seeded Gilles Simon of France defeated Dudi Sela of Israel 6-4, 6-2 and will next meet Lukasz Kubot of Poland.
Kubot, seeded seventh, beat Marius Copil of Romania 6-3, 6-3.