his greatest success came at the 6th boxing world cup in mumbai in 1990, where he won a bronze medal in the light flyweight category. he defeated jin yang of south korea on points in the preliminaries, and paul weir of scotland in the quarterfinals, also on points. he lost to eventual champion eric griffin of united states in the semi-finals on points. however, unlike most amateur boxing tournaments, the boxing world cup had a third place play-off to decide the bronze medal position. zoramthanga defeated fellow indian boxer dhamendar yadav 17–4 on points to clinch the bronze medal. this was india's first medal in an international boxing tournament outside the asian games.