At the Moscow Olympics, Prokofyev was fourth in the 110 m hurdles and won the gold medal running the anchoring leg of the Soviet 4 × 100 m relay team. At the 1982 European Championships, Prokofyev won the silver medal in the 110 m hurdles and again a gold in the 4 × 100 m relay. At the first World Championships, Prokofyev was eliminated in the heats of the 110 m hurdles, but won a bronze medal as a member of the Soviet 4 × 100 m relay team.