[1] Gémesi won a bronze medal in the 2003 Cadet World Championships in Trapani.

He reached the quarter-finals, where he was defeated by team-mate and reigning Olympic champion Áron Szilágyi.

He was defeated by reigning World champion Veniamin Reshetnikov and came away with a bronze medal.

[3] In the World Championships in Kazan, he was eliminated in the first round by team Olympic champion Oh Eun-seok.

In the team event, Hungary were defeated by Italy in the semi-finals, but prevailed over Russia to take the bronze medal.