GSTAAD, Switzerland (AP) Viktor Troicki returned from a one-year ban for a doping rules violation with victory in the Swiss Open first round on Monday.
Now ranked No. 847, the 28-year-old Serbian beat No. 8-seeded Dominic Thiem of Austria 7-6 (4), 6-4.
Troicki was ranked No. 53 last July when the International Tennis Federation imposed an 18-month ban. He had refused to give a blood sample after losing at the Monte Carlo Masters in April 2013.
The Court of Arbitration for Sport reduced the ban when ruling that Troicki's fault "was not significant." He had argued he felt ill and was scared of needles.
Troicki got a wild card entry from organizers of the Swiss clay court event.
Earlier, fifth-seeded Federico Delbonis of Argentina beat Dustin Brown of Germany 6-3, 6-3.