 Zatsepin akakwanisa kupinda mumakwikwi maviri ekushambira kumaOlympics ezhizha ra2004 kuAthens, nekubvisa nguva yeFINA A-standard yekupinda ye2:02.15 200 m munhu mumwechete kubva kuRussia Championships muMoscow. Akashandawo naMaxim Kuznetsov, Yevgeniy Natsvin, naStepan Ganzey mumakwikwi e4×200 m freestyle relay. Achishambira muchikamu chechipiri, Zatsepin akarekodha kupatsanurwa kwe1:51.75, uye timu yeRussia yakapedza kupisa kwegumi nerimwe chete nenguva yekupedzisira ye7:23.97. 