On Saturday, Conor McGregor, arguably the best pound-for-pound UFC fighter, will ditch the Octagon and gloves for a ring and slightly heavier gloves to take on Floyd Mayweather Jr., arguably the best pound-for-pound boxer of his generation.
We’ve never before seen an MMA-boxing crossover between two stars of this magnitude–not even close, actually–but there have been some instances when noteworthy UFC fighters or boxers tried the other sport.
UFC Fighters Boxing
Perhaps the most noteworthy example would be Anderson Silva. “The Spider,” widely regarded as the greatest mixed martial artist of all-time, twice entered the boxing ring. In 1998, after just two professional MMA bouts, he lost to Osmar Luiz Teixeira via second-round TKO, and in 2005, still before he had joined UFC, he beat Julio Cesar De Jesus via second-round KO.
There were preliminary discussions of a Silva vs. Roy Jones Jr. boxing match, but that never came to fruition.
In 2005, Nick Diaz took time in between his wins at UFC 51 and UFC 53 to box Alfonso Rocha, who was making his professional debut but ultimately went 7-4. The fight went the full six rounds, with Diaz walking away as the winner via unanimous decision.
Diaz has said he would return to the boxing ring, but his UFC contract is currently preventing that from happening.
A year after Diaz’s win, Vitor Belfort, who at the time was a former UFC Light Heayvweight champ, knocked down someone named Josemario Neves three times in the first round, winning his lone professional bout via KO:
Possibly the most successful crossover, KJ Noons spent a lot of time in the 2000’s going back and forth between MMA and boxing. While he was 13-9 in MMA (2-3 in UFC), he went 11-2 in the boxing ring with five knockouts.
Other notable mixed martial artists to dabble in boxing include Donald Cerrone (lost to Geoffrey Spruiell in 2003), Carlos Condit (lost to Donnel Wade in 2004) and Mark Hunt (0-1-1 in two professional fights).
Boxers in MMA Fights
This one is a little less common, but there have been some instances of it happening.
In 1993, Art Jimmerson–who at the time was 25-5 as a professional boxer–made the jump to MMA to fight Royce Gracie at UFC 1. Gracie would win via first-round submission, go on to win the UFC 1 tournament and establish himself as one of the most influential individuals in the sport of MMA.
Not only is that fight somewhat legendary because of what Gracie would eventually become, but also because Jimmerson wore one boxing glove–earning the nickname Art “One Glove” Jimmerson in the process–and humorously never stood even a sliver of a chance.
Video of that fight starts at the 4:25 mark here:
In 2010, heavyweight boxing champ James Toney took on former UFC heavyweight and light heavyweight champ Randy Couture, and once again it was a mismatch of colossal proportions. At UFC 118, Couture took Toney down less than a minute into the fight and ultimately forced a submission a couple minutes later with the greatest of ease.
“It’s unfair to put a guy in there with one discipline, even if he’s trained for several months,” said Dana White, somewhat ironically knowing what awaits the boxing world on Saturday night in Las Vegas.