Ivan Koloff was an underrated perfomer in the squared circle. WWE

Former WWE champion Ivan Koloff has died following a battle with liver cancer. He was 74. 

WWE confirmed the news on Saturday via Twitter.

Known as “The Russian Bear,” Koloff (Oreal Perras) was one of the top main-event villains in pro wrestling throughout the 1970 and 1980s. He won arguably the most famous match of the 1970s, pinning the popular WWWF world champion Bruno Sammartino in Madison Square Garden to win the title before a stunned capacity crowd on Jan. 18, 1971. Koloff lost the title to Pedro Morales three weeks later.

While Koloff remained a main-event star, he was so legitimately despised by fans that his hasty departure from the WWWF in March of 1971 was reportedly out of safety fears due to irate fans.

Originally from Montreal, Quebec, Canada, Koloff debuted in 1961, settling on the Irish character of “Red McNulty” early on. He began performing as Russian villain Koloff in 1967 and spent the next three decades wrestling all over the world as a top heel.

In the 1980s, Koloff played a key role in the NWA Mid-Atlantic territory, which was run by promoter Jim Crockett and would eventually become World Championship Wrestling (WCW). In the mid-80s, he teamed with “nephew” Nikita Koloff (Scott Simpson) and Krusher Khruschev (Barry Darsow, the future Demolition Smash) as a three-man Russian team that feuded memorably with the Road Warriors and the Rock ‘n’ Roll Express.