After switching to freestyle wrestling Kumar's first success came at the World Cadet Games in 1998 where he won the gold medal in his weight category, followed by a gold at the Asian Junior Wrestling Championship in 2000. Moving out of the junior competitions, in 2003 Kumar won the bronze medal at the Asian Wrestling Championships and a gold at the Commonwealth Wrestling Championships. Kumar placed fourth at the 2003 World Championships, but this went largely unnoticed by the Indian media as he fared badly in the 2004 Olympic Games in Athens, placing 14th in the 60 kg weight class.