Bucharest - Defending champion Lukas Rosol won his eighth successive match at the Nastase Tiriac Trophy by eliminating fourth-seeded Gilles Simon 7-6 (2), 6-2 in the quarter-finals on Friday.
The unseeded Czech defeated Simon, Bucharest's only three-time champion, for the second year in a row.
Rosol won last year in the semi-finals en route to his first and only ATP title.
On Saturday, Rosol will meet Robin Haase of the Netherlands, who converted five of his 11 break points in a 3-6, 6-1, 6-3 victory over Denis Istomin of Uzbekistan.
Also in action were top seed Grigor Dimitrov against Sergiy Stakhovsky, and third seed Gael Monfils facing Paul-Henri Mathieu in an all-French affair.
Quarter-finals:Grigor Dimitrov (BUL x1) bt Sergiy Stakhovsky (UKR) 6-3, 6-4
Gael Monfils (FRA x3) bt Paul-Henri Mathieu (FRA) 3-6, 7-6 (10/8), 6-2
Lukas Rosol (CZE) bt Gilles Simon (FRA x4) 7-6 (7/2), 6-2
Robin Haase (NED) bt Denis Istomin (UZB) 3-6, 6-1, 6-3