At the 1962 British Empire and Commonwealth Games, hosted in Perth, Vlahov was one of four Australians selected to compete in the men's discus event. He placed sixth overall with a throw of , and was the second-best Australian behind gold medallist Warwick Selvey. Vlahov also represented Australia at the 1967 Summer Universiade in Tokyo, and served as the flag-bearer. He threw to place fourth overall, landing behind bronze medallist Neal Steinhauer of the United States.