Džomba was selected to play at the World Championship in 2003. Croatia started the tournament with a loss against Argentina. In their second match Croatia beat Saudi Arabia 18:25. Next they beat Russia (26:28), France (23:22) and Hungary (30:29). Croatia proceeded to second phase of the competition where they beat Egypt (29:23) and Denmark (33:27). In the semi-finals Croatia defeated Spain 37:29 in overtime. Džomba scored 22 goals in the tournament 8 of them in the final match against Germany where Croatia won 34:31 and became World Champions. Džomba was voted best right wing of the tournament and placed in the tournament all star team.