In the FIS Nordic World Ski Championships, Mateja's best finishes were fifth in the large hill individual event in Trondheim (1997) and fifth again in the large hill team event in Sapporo (2007). His best finishes at the Winter Olympics were fifth in the large hill team event (2006) and 20th in the large hill individual event (1998). In the Ski Flying World Championships he finished eighth in the 2004 team event and 19th in the 2006 individual event. At Continental Cup level he scored three individual victories in 2003, 2004 and 2007.