Early career Moumtzis made his professional debut on November 4, 2018 against Hunter Mohamed. Moumtzis won the fight via Unanimous Decision.
Messapicum Fighting Championship Featherweight champion After accumulating a record of 3–0, Moumtzis faced Willman Junior Cuellar for the vacant Messapicum Fighting Championship Featherweight championship on December 21, 2019. Moumtzis won the fight via Unanimous Decision, and thus won his first career championship.
Quest MMA and Athens Fighting Championship After over a year out, Moumtzis made his debut with Quest MMA on July 8, 2021 against Markus Held. Moumtzis won the fight via a first-round TKO. Moumtzis made his debut with Athens Fighting Championship on June 3, 2022 in a rematch against Hunter Mohamed. Moumtzis would once again be victorious over Mohamed by winning via Unanimous Decision. Moumtzis returned to Quest MMA on October 16, 2022 against Spartakos Tselaridis. Moumtzis won the fight via a second-round TKO. After just over two years out, Moumtzis returned on October 27, 2024 against Konstantinos Leonidou. Moumtzis won the fight via Unanimous Decision.
Cage Warriors Moumtzis made his debut with British federation
Cage Warriors on April 19, 2025 against Keir Harvie. Moumtzis won the fight via Unanimous Decision. ==Championships and accomplishments==