Serena Williams beats 2009 Australian Open Svetlana Kuznetsova in three sets . World number one to beat last year 's runner - up Sara Errani in last four . Italian advance to semifinals after beating Agnieszka Radwanska in straight sets .
Serena Williams beats 2009 French Open Svetlana Kuznetsova in three sets . World number one to face last year 's runner-up Sara Errani in last four . Italian returns to semifinals after beating Agnieszka Radwanska in straight sets .