DORNEY  - Czech Republic's Miroslava Knapkova powered to victory in the women's Olympic single scull on Dorney Lake on Saturday to add to her 2011 world championship title and finally confirm her position at the top of the sport. The 31-year-old had a strong start and led by over a length by 500 metres and established more than a boat's length of clear water before 1,000 metres in one of the most dominant finals of the regatta. Denmark's unheralded Fie Udby Erichsen took silver and Australia's Kim Crow the bronze.