 Her withdrawal also meant that she and older sister Venus could not pair up to defend the doubles title they won in 2009, and allowed WTA No.2 Caroline Wozniacki to be installed as the top seed for the tournament, where she was defeated in the semi-finals by Vera Zvonareva.It was the first time since 2003 in which Serena Williams was forced to miss her national championships due to injury, the first Grand Slam tournament she missed through injury since Wimbledon in 2006, the first time since the 2007 Australian Open in which the women's World No.