Before retiring as an alpine skier, Kraus had already taken up ski cross. He made his World Cup debut in November 2002 in Tignes, and won that race, but only competed in two more races that season. He opened the 2003–04 season with an eighth place in Saas-Fee, and recorded a fourth place from Pozza di Fassa in January as his best result. In the 2004–05 season he competed in six World Cup races, winning three of them; in Les Contamines, Pozza di Fassa and Kreischberg. At the end of the season he won the gold medal at the 2005 World Championships in Ruka.