Melyoshin represented Kazakhstan at the 2008 Summer Olympics, where he competed for the men's 74 kg class. He defeated Australia's Hassan Shahsavan in the preliminary round of sixteen, before losing out the quarterfinal match to Belarus' Aleh Mikhalovich, with a three-set technical score (1–1, 1–1, 1–2), and a classification point score of 1–3.[4]