Australias Samantha Stosur clinched her at the outset impressive slam by winning the U.S. commence within September.STORY HIGHLIGHTSSamantha Stosur books her place in the sphere of the semifinals by the WTA ChampionshipsStosur crushes Chinas Li Na 6-1 6-0 to sign up get-together with Petra KvitovaVera Zvonareva to stand facing Victoria Azarenka in the sphere of the other semi behind Agnieszka Radwanskas defeatRadwanska fails in the sphere of her undertaking to prepare after everything else four behind a straight sets defeat by Kvitova U.S. amenable champion Samantha Stosur stormed into the semifinals of the season-ending WTA Championships similar to crushing Chinas Li Na 6-1 6-0 hip Istanbul.