In December 2001, Zupan competed in an international competition for the first time at the Continental Cup (COC) in St. Moritz . At the Junior World Championship held in Schonach in January 2002 , he and the team won the bronze medal. During the summer ski jumping held as part of the Continental Cup, he was able to achieve a place among the top ten in an international individual competition for the first time on September 21, 2002 in Calgary with a ninth place. In winter 2002/03 he competed continuously in the Continental Cup and was able to win a podium for the first time with a second place in jumping in Braunlage in early February . In the summer of 2003 he again took part in the COC and was able to occupy top positions.
At the beginning of winter 2003/04 he started again in the Continental Cup, but was able to qualify for the World Cup for the first time in Liberec in early January . The rest of the season he went back to the COC, but took part in the Ski Flying World Championships 2004 in Planica . Although he was not used in the individual competition, he started in the team competition and reached sixth place with the Slovenian team. In the first half of summer 2004 he started in the COC jumping competitions, where he celebrated the first victory of his career in jumping on July 9, 2004 in Velenje . In the second half he started in the Grand Prix show jumping , with a 21st place in Hakuba being his best result.
In the 2004/05 season he got several appearances in the COC and eight appearances in the World Cup. He always fought for a place in the second round and finished in 72nd place in the overall standings. He did not take part in the summer of 2005, in the winter of 2005/06 he mostly took part in the Continental Cup, but was also able to compete in some World Cups. This season should be his best in the Continental Cup: In jumping on March 11th in Bischofshofen he could celebrate another victory and in the end he finished 13th in the overall ranking. After the end of the 2006 season in Planica, where he finished 26th and 25th, Zupan ended his active ski jumping career.