The last remaining seed tumbled out of the Antalya Open on Thursday, leaving four unseeded players in the hunt for the title.
Third seed Fernando Verdasco of Spain fell 6-2, 5-7, 6-2 to Frenchman Adrian Mannarino to continue the exodus of big names at the inaugural Turkish grass court event.
Mannarino was serving to stay in the match at 4-5 in the second set, but rallied superbly from there, winning nine of the last 11 games to wrap up victory in one hour and 50 minutes.
Awaiting Mannarino in the semi-finals is Italy's Andreas Seppi, who beat Radu Albot 6-4, 7-6 (7-3) in a tight battle.
The second semi-final sees former World No 8 Marcos Baghdatis take on Japan's Yuichi Sugita.
Baghdatis needed close to three hours before finally beating qualifier Ramkumar Ramanathan 6-7 (0-7), 6-3, 7-6 (8-6).
Sugita, a Challenge Tour regular, took just 49 minutes to dispatch Daniel Altmaier 6-3, 6-0 and advance to his first ever ATP World Tour semi-final.