This caused her ranking to fall to World No. 19 .
Following the US Open , Pe'er chose not to defend the back - to - back titles she won in 2009 at the Guangzhou International Women 's Open and the Tashkent Open .
This caused Pe'er 's ranking to fall to World No. 19 .
Following the US Open , Pe'er chose not to defend the back - to - back titles she won in 2009 at the Guangzhou International Women 's Open and the Tashkent Open .