When Buster Douglas defeated Tyson he wrote not just boxing history but also betting history. To this date we still don’t have any upset that even comes remotely close. Not only is it the biggest upset in boxing in history but it’s the biggest upset in combat history period.
The 42 to 1 underdog was going up against Tyson in february, 1990. Tyson at the time had never lost a single fight in his life, he was coming off his peak performance in the late 80s where he had teared up the heavyweight division. So ofcourse, everyone expected Tyson to run through Douglas like a samurai sword through butter. Douglas definitely didn’t have a bad record himself or was an unknown fighter but he never seemed to put everything together. In fact, after he defeated Tyson there was a lot of hype, many people expected Douglas to be the next big thing but it all came down crashing quick when he lost the following fight by KO versus Holyfield.
To put this upset in to perspective in comparsion to other big upsets in Boxing & MMA:
Muhammed Ali was 4 to 1 underdog vs George Foreman.
Matt Serra was 13 to 1 underdog versus GSP.
Fabricio Werdum was a 4 to 1 underdog vs Cain Velasquez.
Bigfoot Silva vs a 4-1 underdog vs Fedor Emelianenko.