NEW DELHI, July 27: Asian silver-medallist Shiva Thapa (60kg) was assured of at least a bronze medal as he entered the semifils along with three others on an all-win day for India at the Grand Prix Usti d Labem boxing tourment in Czech Republic. Shiva defeated local favourite Erik Huleiv in a unimous verdict to enter the last-four stage last night. Three others Indians were also assured of bronze medals after getting byes. They were Gaurav Bidhuri (56kg), Kavinder Bisht (52kg) and Amit Phangal (49kg).