Nansen practised
kung fu as a child and grew up playing
rugby league. He began training in
kickboxing at the age of 21. He is the cousin of
Ray Sefo. He holds a professional
kickboxing record of 22 wins and 3 loss, and has been the kickboxing champion of
New Zealand in three different weight classes. He defeated Joel Martin in October 2008 to become the World Kickboxing Federation (WKBF) Heavyweight Kickboxing Champion of New Zealand. On 23 September 2009, he made his
mixed martial arts debut against Olympic
judoka
Hiroshi Izumi at
World Victory Road Presents: Sengoku 10 in
Saitama,
Japan. Nansen was able to control the fight with his
striking and won via
technical knockout in the first round. The following year, on 25 April, Nansen took part in his second MMA bout at ''ASTRA: Yoshida's Farewell'' against
jiu-jitsu fighter Enson Inoue, who was making his return to the ring after six years of retirement. Inoue used his superior
grappling skills to win via
submission by using an
armbar in round 1. He was then set to face
Satoshi Ishii, another of Japan's Olympic judoka, at the
K-1 World MAX 2010. However, Nansen was unable to compete ==Titles==