Advena made his Olympic debut in Athens 2004, competing in two swimming events. He also teamed up with Maksym Kokosha, Dmytro Vereitinov, and Olympic stalwart Serhiy Fesenko in the 4 × 200 m freestyle relay. Swimming the anchor leg, Advena recorded a fastest split of 1:50.90, and the Ukrainian team went to finish the preliminary heats in twelfth overall, with a final time of 7:24.13. In the 200 m butterfly, Advena failed to qualify for the final, as he finished twelfth overall in his semifinal run in 1:58.11. His time was just two hundredths of a second (0.02s) ahead of Japan's Takeshi Matsuda, who beat him for the gold medal at the 2003 Summer Universiade in Daegu, South Korea.