While it will likely have none of the animosity of that famous showdown between Billie Jean King and Bobby Riggs (which, incidentally, was 40 years ago this week), Beijing will stage its own Battle of the Sexes on Friday September 27 when women’s world no. 5 Li Na will play men’s world no. 1 Novak Djokovic at the National Tennis Center in northern Beijing to mark the 10th anniversary of the China Open.