In May 1960, the American Wrestling Association (AWA) named O'Connor as the first holder of the AWA World Heavyweight Championship. However, he never defended the AWA World Heavyweight Championship, and was stripped of it in August, after ninety days, when Verne Gagne was recognized as the new champion.
On November 10, 1967, the team of O'Connor and Wilbur Snyder defeated Larry Hennig and Harley Race to win the AWA World Tag Team Championship. They lost the titles on December 2 to Mitsu Arakawa and Dr. Moto.
On November 16, 1987, O'Connor participated in a World Wrestling Federation "old-timers" battle royal, which was won by Lou Thesz.
On August 16, 1990, O'Connor passed away.
In 2016, O'Connor became a "Legacy" member of the WWE Hall of Fame.