komt uit Houthalen-Oost Brecht Wallis started training in judo at the age of 12 and a few years later moved on to Muay Thai.
He made his K-1 debut in 2003 at K-1 Holland GP in Zoetermeer, winning the bout against Swedish fighter Jorgen Kruth by extra round majority decision.
On 14 February 2004 Brecht won his first K-1 tournament in Stockholm, Sweden qualifying for K-1 World GP 2004 in Las Vegas II.
In the quarter-finals he was matched up against heavy favorite, American Carter Williams, Wallis won the fight by spectacular high kick in round 3.
After an evenly fought match Brecht Wallis was announced the winner by unanimous decision and moved on to the tournament finals against American Mighty Mo where he suffered his first loss by a devastating KO in a second round.