Wanz made his pro wrestling debut in 1968 working in and around his native Austria. Later on he would work as "Bulldog" Otto in Japan, primarily working for New Japan Pro Wrestling (NJPW). In the early 1970s he created the Catch Wrestling Association based in Austria but promoting shows in the surrounding countries as well. On August 2, 1973 Wanz defeated Jan Wilkens on a show in Cape Town, South Africa to become the first holder of the CWA World Heavyweight Championship, bringing the championship back to Europe once the tour was over. Over the next two years Wanz defended the championship in Austria and Germany on several occasions, before losing to Don Leo Jonathan on September 1 in Johannesburg, South Africa. Wanz brought Don Leo Jonathan to Graz, Austria to win the championship for a second time in front of a home town crowd. Over the years Wanz toured the United States, wrestling for various promoters. While in the US during a 1982 tour he worked for Verne Gagne's American Wrestling Association (AWA) where he defeated long-reigning AWA World Heavyweight ChampionNick Bockwinkel to win the AWA title. The reign ended 41 days later as Bockwinkel regained the championship. There have been persistent rumors that Wanz actually paid Gagne for the title run but that has never been confirmed by anyone. Returning to the CWA Otto Wanz spent several years as the champion until March 22, 1987 where an American power house wrestler known as Bull Power defeated him for the championship. Wanz regained the title a few months later but Bull Power would start a second reign in 1989. During Bull Power's CWA reign he became a champion in Japan and Mexico as well under the name Big Van Vader. On June 30, 1990 Otto Wanz won the CWA Championship for a fourth time. Immediately after the match Wanz retired from active competition to focus on promoting the CWA.