Dežman made his international debut in 2008 at the FIS Junior Competitions. In December 2008, at the age of 18, he competed in the FIS Cup for the first time . With just nine points from the FIS Cup season 2008/09, he finished 210th overall. At the Slovenian Ski Jumping Championships in Kranj in 2009 , he reached fifth place in team jumping together with Matej Dobovšek , Jure Bogataj and Rok Urbanc . After two top 20 placements in the Ski Jumping Alpine Cup in Oberstdorf in October 2009, he also started in the FIS Cup in the 2009/10 season. However, he did not get beyond a 211th place in the overall standings. After another rather unsuccessful appearance in the 2010 Alpine Cup, he started for Slovenia at the Nordic Junior World Ski Championships 2011 in Otepää, Estonia . There he reached 5th place with the team in the team competition and 39th place in the individual competition.
On February 20, 2011, he made his debut in the Ski Jumping Continental Cup on his home hill in Kranj , but only achieved 47th place. After he started the rest of the season in the FIS Cup and the Alpine Cup, he got the chance to start again for the Summer Continental Cup in July, but was disqualified. In September 2011 he achieved sixth place in Klingenthal, his best result to date in the Continental Cup and also for the first time a place among the top ten. From the 2011/12 winter season he was a permanent member of the Slovenian Continental Cup squad and consistently achieved points. Therefore, on January 15, 2012, he was given the opportunity to compete in the Ski Jumping World Cup for the first time on Kulm . In ski flying , he did not reach the second round in both competitions and ended up in 41st and 51st.
In February 2012 Dežman won the gold medal in the individual competition at the Nordic Junior World Ski Championships in Erzurum, Turkey . With the team he just missed the podium with fourth place. With his gold medal, he also got the opportunity to jump in the World Cup team after the Junior World Championships and immediately qualified in Lahti and won his first World Cup points in jumping with 29th place. Also in Trondheim and Oslo , where he achieved his best World Cup result with 17th place, he achieved placements within the points. At the end of the season Dežman finished 61st place overall.
After Dežman could not convince in the Continental Cup in the summer of 2012, he stayed in the Continental Cup squad for the 2012/13 season . In two World Cup appearances in Sapporo, Japan, in January 2013, he missed the second round with places 45 and 50 and even missed qualification at the World Cup in Vikersund . In February at the Continental Cup on the Bloudkova Velikanka in Planica , he reached places 12 and 13 again within the top twenty.
In summer 2013 Dežman celebrated the first Continental Cup victory of his career in his home town of Kranj . His first win on the Continental Cup on snow was on January 16, 2013 on the Miyanomori hill in Sapporo . The next day he followed up with his second victory.
Dežman announced the end of his career in mid-June 2019. His last jump was on the weekend of the Continental Cup in his home town of Kranj in early July.
Slovenia
Willingen
Sapporo
Erzurum
