Ekaterina Bychkova (born June 5, 1985) is a professional tennis player, born in Moscow, Russia. She is most famous for defeating defending champion Svetlana Kuznetsova is the first round of the 2005 U.S. Open. She defeated her by a score of 6-3, 6-2. It was the first time a defending U.S. Open Champion had lost in the first round. The win didn't last for long; Bychkova lost in the second round to Ivana Lisjak.