Sixth seed Viktor Troicki was an early casualty on the opening day of the BRD Nastase Tiriac Trophy in Bucharest on Monday.
The Serbian world number 34 was out-lasted by Spanish opponent Daniel Gimeno Traver who 5-7 6-3 6-1 to book his place in the second round.
Croatian teenager Borna Coric held his nerve to pull off a 6-2 6-7 (4/7) 7-6 (7/2) win over experienced Ukrainian Sergiy Stakhovsky.
The 18-year-old Coric will face his big-serving countryman Ivo Karlovic in the second round.
Tunisia's Malek Jaziri beat Florian Mayer of Germany 4-6 6-4 7-5, and Mikhail Youzhny shrugged off a nightmare first set to beat Romania's Marius Copil 1-6 6-4 6-3.
Source: PA
