[1] Koutsioumpas represented his home nation Greece at the 2004 Summer Olympics in Athens, and later picked up a silver medal in the 96-kg division at the 2005 Mediterranean Games in Almería, Spain.

Koutsioumpas qualified as a member of the Greek squad in the men's 96 kg class at the 2004 Summer Olympics in Athens by receiving an allocated place and an automatic spot for the host nation from the International Federation of Associated Wrestling (French: Fédération Internationale des Luttes Associées, FILA).

[4][5] By the delight of the boisterous home crowd inside the Ano Liossa Olympic Hall, Koutsioumpas opened his match by edging Kazakhstan's Asset Mambetov out of the mat with an effortless throw, but suffered a tedious 6–11 blowout from Egypt's Karam Gaber on his second bout.

Despite a single loss, Koutsioumpas continued to grapple powerfully against Poland's Marek Sitnik and paid off by a 3–2 sudden death decision.

When Iran's Masoud Hashemzadeh was disqualified for an illegal protest during the bronze medal match, Koutsioumpas' position was eventually upgraded to seventh.