As a member of the Cyprus team, Papachrysanthou made his official debut at the 2000 Summer Olympics in Sydney, where he competed in the men's 100 m freestyle. He rounded out the fifth heat to last place and fifty-seventh overall by 0.04 of a second behind Ecuador's Felipe Delgado in 52.82. By the following year, Papachrysanthou shared silver medals with France's Julien Sicot in the 50 m freestyle at the 2001 Mediterranean Games in Tunis, Tunisia in 23.06 seconds.