Jensen competed in three swimming events, including all freestyle relays, for Denmark at the 2000 Summer Olympics in Sydney. He achieved a FINA B-cut of 55.31 (100 m butterfly) from the European Championships in Helsinki. In the 100 m butterfly, Jensen challenged seven other swimmers in heat four, including Yugoslav teenager Milorad Čavić (aged 16), who later disqualified for a false start. He raced to a fifth seed and forty-second overall by almost a full body length behind winner Simão Morgado of Portugal in 55.70. A member of the Danes, he also placed eighteenth in the 4×100 m freestyle relay (3:24.78), and eleventh in the 4×200 m freestyle relay (7:24.63).