After taking up Muay Thai at thirteen years old, he began his career in 2004 and rose to prominence by becoming a five-time national champion at both amateur and professional levels.
[2] After amassing around seventy bouts in amateur competition, Bessmertny turned professional and soon became a five-time national champion, three times under Oriental rules[broken anchor] and twice in Muay Thai.
Bessmertny floored local fighter Norbert Balogh in rounds one and three en route to a unanimous decision win in the semis and came up against Thai star Sudsakorn Sor Klinmee in the final.
Sudsakorn struggled with stamina problems throughout and Bessmertny was able to pick him apart over the three rounds to take another unanimous points victory, earning himself the tournament title and $80,000 in prize money.
[23][24] Bessmertny returned to Fight Code to compete in the 2012 Dragons Series, which was expanded to thirty-two participants, and took a lackluster points win over Edvin Erik Kibus at the opening stage in his hometown of Minsk on April 14, 2012.
In his next outing, he fought to a draw with Issam Reghi at La Nuit des Challenges 11 in Lyon, France, on June 2, 2012[28] and, having gone undefeated in the first half of the year, moved up to #5 in the world rankings in July 2012.
[30][31] Bessmertny made his return against Roberto Cocco at a weight of 75 kg/165 lb at another Thai Boxe Mania event in Torino on November 24, 2012, and won by TKO due to a cut in round two.
[33] Bessmertny took on his second Thai opponent in the form of Aikpracha Meenayothin in the semi-finals of a four-man tournament at La Nuit des Titans 2013 in Tours, France, on February 2, 2013.