It has been called a circus event but Saturday's curiosity show between Floyd Mayweather Jr and Conor McGregor is nothing new.
In the first half of the last century, boxing champions were fighting wrestlers to pull in punters for events that were more about entertainment and making money than sport.
How was it seen at the time -- a real fight, or a farce?
Dempsey destroys wrestling rival
Jack Dempsey was 45 when he fought wrestler Clarence 'Cowboy' Luttrell, 13 years after the Manassa Mauler's last official fight for the world heavyweight title against Gene Tunney.
The boxing contest on July 1, 1940 came 21 years after the start of Dempsey's s reign as world heavyweight champion (1919-1926). Dempsey was then in need of some money -- it was a few years before his New York restaurant would take off -- and he had just separated from his third wife.
Dempsey was making a living as a wrestling referee when he first met Luttrell. Their rivalry began when Luttrell took a swing at Dempsey, then refereeing one of Luttrell's wrestling bouts. It led to a war of words, albeit a lot tamer than what we have seen between Mayweather and McGregor, via the newspapers.
"I've licked tougher guys than Jack Dempsey," said Luttrell, from Texas. "There's never been a boxer who could beat a good wrestler. I want to be known as the guy who KO'd Dempsey."
Reported by the Associated Press, Dempsey hit back: "Have you ever seen a wrestler who can fight?
"I think I can get this over with in a hurry. I've got all my old time punch but of course my legs aren't what they used to be and my wing may be short. That's the reason I will cut loose for a quick knockout."
Luttrell responded: "I'm 11 years younger than Dempsey and am in far better physical condition."
It created such interest that Dempsey was met by thousands of fans when he arrived by train in Atlanta for the fight at the Ponce de Leon Park, where a reported 10,000 turned up. In another parallel to Mayweather-McGregor, Dempsey demanded the use of the lightest gloves possible (six ounces).
Dempsey lived up to his promise as he knocked Luttrell senseless in four minutes and 58 seconds. It was a one-way slaughter that was allowed to continue too long before 224 pounds grappler Luttrell was knocked spectacularly head over heels through the ropes.
Luttrell was taken to hospital and the fight reportedly grossed $15,000 -- small change for Dempsey who had drawn the first million-dollar gate for his first fight with Tunney in 1921. Dempsey reportedly earned just $5,000, Luttrell $800.
And yet in the ensuing weeks Dempsey fought two others wrestlers, Bull Curry and Ellis Bashara, in lower profile events which were equally sad spectacles for the former champion, once the most recognisable face in sport.
Wrestling with finances
Joe Louis never dreamed of a wrestling career after his boxing days, but the former world heavyweight champion was forced into it due to crippling debts.
Faced with unpaid taxes of over $1million, Louis traded in his dignity to grunt and roll around a wrestling mat. He made his wrestling debut in 1956 against Cowboy Rocky Lee, five years after the long overdue finish of his boxing career.
As was the case when other boxing champions became wrestlers, it was a novelty act that created curiosity for a while and 4,000 turned up to see it in Washington, DC. But for Rose Morgan, his wife at the time, it was not a pleasant sight.
"To me, Joe Louis is like the President of the United States," she said. "How would you like to see the President of the United States washing dishes? That's how I feel about Joe wrestling."
Louis did not last long at wrestling, but his former opponent Primo Carnera took it seriously for many years.
Italian Carnera, who briefly reigned as world heavyweight champion between 1933 and 1934, became a wrestler in 1946 and continued grappling until the 1960s. He was a success in the sport, perhaps more so than boxing, with wins over the likes of Ed 'Strangler' Lewis.
But for others wrestling was strictly a necessity in retirement from the ring. Former world heavyweight champion Ezzard Charles became a wrestler 11 years after beating Louis in a title defence after he had squandered his ring earnings.
England's Randy Turpin, who won the world middleweight title from the great Sugar Ray Robinson in 1951 and then lost it in a rematch later in the year, was another who had an inglorious wrestling career after boxing due to unpaid tax.
Even the Greatest...
Muhammad Ali -- then the world's best boxer -- fought Antonio Inoki-- then Japan's best wrestler -- to a large worldwide audience on closed circuit television on June 25, 1976. It was perhaps Ali's least memorable fight.
A year after the 'Thrilla in Manilla' with Joe Frazier, one of boxing's most thrilling, Ali went through with this surreal money-earner -- reportedly worth $6m to him, $3m for Inoki -- that ended in a 15-round points draw.
The only losers were the punters who paid to see it. Ali threw few punches and Inoki spent most of the 'fight' on the floor kicking. By laying on the floor and scuttling about the ring like a crab kicking upwards, Inoki ensured Ali could not hit him at the Nippon Budokan arena in Tokyo.
"It all proved boxers are superior to wrestlers," said Ali, then 34 and the reigning world heavyweight champion. "He didn't stand up and fight like a man." But wounds from the kicking left Ali with infected cuts and two blood clots.
"It was the low point of my career," said promoter Bob Arum. "It was so embarrassing, just a total farce."
Bear necessities
A year after losing to Muhammad Ali, heavyweight contender Chuck Wepner fought a 7ft 5in, 525-pound wrestler called Andre the Giant -- real name Andre Roussimoff -- in front of 30,000 people at the Shea Stadium on the same night as Ali-Inoki. Wepner was never a world champion, but his encounter with Andre the Giant is one of the most infamous meetings between a boxer and a wrestler.
It was a pantomime event, where anything went and culminated in Wepner -- the inspiration behind the Rocky movies -- being thrown out of the ring by Andre, who was not wearing boxing gloves, in the third round.
But Wepner was involved in an even bigger freak show when he wrestled with a bear -- twice. In what were definitely not sports events, Victor twice got the better of the boxer for charity.
"He probably mauled and beat up a thousand people in his career because he fought almost every week," Wepner told BBC Radio 5Live.
"He was muzzled but he was so strong and it was like running into a brick wall, but I tried not to get too close to him. The first time he threw me off the mat, a good 20 feet, and I landed on the gym floor. He then landed on top of me straight away.
"The second time [they fought] it was a dinner show, a fundraiser. I'm sitting in the corner looking at him, with his beady eyes, and I said to my trainer this bear remembers me. The bell rang and he stood straight up in his corner, let out with a roar. I started to get out of the ring and he grabbed my leg and swung me like a rubber band and I went eight or ten feet in the air and landed on a dinner table."