Question: In the 2013 Citi Open – Women's Doubles, Aoyama successfully defended the title alongside Vera Dushevina, defeating Eugenie Bouchard and Taylor Townsend in the final, Bouchard is a Canadian professional tennis player, and became the first Canadian-born player representing Canada to reach the finals of a Grand Slam in singles, finishing runner-up to who?
Answer: Petra Kvitová