Perrelli won Melodifestivalen 2008 on march 15 , she represented Sweden in the Eurovision Song Contest 2008 in Belgrade , Serbia . On March 15 , 2008 Perrelli performed and won Melodifestivalen 2008 again with her song `` Hero '' at the Stockholm Globe Arena . She went on to represent Sweden in the Eurovision Song Contest 2008 in Belgrade , Serbia , where she advanced to the finals .