In 1986, The Berzerker debuted as Nord the Barbarian in the American Wrestling Association (AWA) and wrestled in singles and tag team matches (under manager Sheik Adnan El-Kaissey). Here, he frequently teamed with Bruiser Brody. The two faced Greg Gagne and Jimmy Snuka as part of a triple main event at WrestleRock '86.
Nord then went to World Class Championship Wrestling in 1987. He was managed by Gary Hart, where he feuded with Kevin Von Erich.
In 1989, he returned to the AWA under the name Yukon John (a lumberjack gimmick where he would come to the ring with an ax, dressed in blue jeans, flannel shirt, animal skin hat and boots). He mainly competed in singles matches, until forming a tag team in 1990 with Scott Norton, called The Yukon Lumberjacks. They briefly feuded with The Texas Hangmen.
In 1991, Nord joined the World Wrestling Federation (WWF) as The Viking. He soon became The Berzerker (managed by Mr. Fuji) and feuded with Davey Boy Smith and Jimmy Snuka. His preferred method of winning matches was by throwing his opponents over the top rope for a countout, all the while holding his wrist, licking his hand, shouting "Huss! Huss!", and falling flat on his back. He wrestled as part of a four-man team in an elimination match at the 1991 Survivor Series pay-per-view event. He was the last man eliminated for his team. He then feuded with The Undertaker, at one point attempting to stab him with his sword. He also wrestled in the 1992 Royal Rumble. In July 1992, he won a 40-man battle royal on WWF Prime Time Wrestling, and challenged Bret Hart for the WWF Championship that November. The Berzerker's final appearance was as a participant in a battle royal on the February 15, 1993 edition of Monday Night Raw.
In 1997, The Berzerker joined World Championship Wrestling (WCW) with bleached blond hair and a fu manchu moustache, under his real name, John Nord. He wrestled mainly on WCW Saturday Night and had a long winning streak that ended with a loss to another streak holder, Bill Goldberg, on July 4, 1998. Nord then formed a short-lived team with Barry Darsow, and was soon gone from WCW.