The Swiss number two Stanislas Wawrinka won his opening match in group A of the ATP World Finals today against Tomas Berdych 6-3 6-7 6-3. It is the first year Wawrinka has qualified for the event. There was also a victory tonight for Juan Martin Del Potro in group B defeating Frenchman Richard Gasquet 6-7 6-3 7-5.