DEN BOSCH (Agencies) - Kim Clijsters lost in the second round of the Unicef Open to Romina Oprandi 7-6 (5), 6-3 on Tuesday, a premature end to the world number two's Wimbledon preparations. Clijsters skidded to the net and stumbled in just the second game and appeared tentative throughout the match, although she did not call for any medical treatment and it was not clear if she injured an ankle. Oprandi repeatedly surprised Clijsters with heavily sliced backhand drop shot winners, many of them off Clijsters' serve. It was Clijsters' second straight second-round exit, after losing to Arantxa Rus at the same stage of the French Open.