Boxing is the sport where anything can happen. Odds mean nothing when the bell rings. A single punch can end a fight, and a single fight can end a legacy. The greatest upsets in boxing history all share the same story: a fighter written off before he walked to the ring finding the performance of his life on the night that mattered most.
The list below spans nearly a century, from the golden age of the 1930s and 1940s to the modern era of pay-per-view heavyweight boxing. Some of these fighters became household names on the back of a single night. Others faded almost as quickly as they arrived. But every result on this list rewrote the sport, and several of them made a fortune for anyone bold enough to back the underdog at the sportsbooks the night before.
This is our ranked list of the ten biggest upsets in boxing history. Each entry covers the odds, the story and the shockwave that followed. For the odds on the next big fight, head over to boxing betting at BetVictor.
1. Buster Douglas KO 10 Mike Tyson (11 February 1990)
The greatest upset in boxing history, and arguably the greatest upset in any professional sport. Mike Tyson entered the Tokyo Dome as the undefeated, undisputed heavyweight champion of the world at 37-0 with 33 knockouts. James “Buster” Douglas, a journeyman from Columbus, Ohio, had already blown one world title shot against Tony Tucker three years earlier. The oddsmakers listed Douglas as a 42-1 underdog and most Las Vegas books stopped taking bets on the fight altogether.
Douglas had lost his mother 23 days before the fight. He fought with a chip on his shoulder and a jab that never stopped, and he refused to fold when Tyson dropped him in the eighth round. Douglas beat the count, walked back onto Tyson in the ninth and knocked out the most feared heavyweight of his generation with a four-punch combination in the tenth. Tyson was floored for the first time in his career, groping for his mouthpiece on the canvas. Boxing has never been the same. A £100 bet on Douglas at BetVictor odds equivalent would have returned £4,300.
2. Andy Ruiz Jr TKO 7 Anthony Joshua (1 June 2019)
The most seismic upset of the modern era, and the closest anyone has come to matching Douglas versus Tyson since. Anthony Joshua walked into Madison Square Garden as the unified WBA, IBF and WBO heavyweight champion, undefeated at 22-0 with 21 knockouts, ready for his long-awaited US debut. Andy Ruiz Jr was a late replacement after Jarrell Miller failed a drug test, listed at 25-1 by British bookmakers and openly dismissed as a soft touch on his way to a big-name payday.
Ruiz walked to the ring looking two divisions too small for the champion. Then he dropped Joshua twice in the third round, twice more in the seventh, and forced referee Michael Griffin to stop the fight. Joshua lost the WBA, IBF and WBO titles in the space of nine minutes. The rematch six months later in Saudi Arabia saw Joshua reclaim his belts on points, but the first fight remains the biggest heavyweight upset of the 21st century.
3. Muhammad Ali KO 8 George Foreman (30 October 1974)
The Rumble in the Jungle. George Foreman was, in the eyes of most observers, unbeatable. He had brutalised Joe Frazier in two rounds, done the same to Ken Norton, and arrived in Kinshasa, Zaire, as a 4-1 favourite over a 32-year-old Muhammad Ali who had lost to both Frazier and Norton in the years since his exile.
Ali produced the strategic masterpiece of the 20th century. He absorbed Foreman’s power against the ropes with what became known as the Rope-a-Dope, allowing the champion to punch himself into exhaustion before finding the finishing right hand in the eighth round. Foreman went down in a corner, spent, and Ali reclaimed the heavyweight title. For the technical breakdown of the shots Ali used to counter Foreman, read our guide to boxing punches explained.
4. Cassius Clay TKO 7 Sonny Liston (25 February 1964)
Before he was Muhammad Ali, Cassius Clay was a 22-year-old former Olympic champion widely believed to be walking into a slaughter. Sonny Liston was the most feared heavyweight of his generation, a two-fight destroyer of Floyd Patterson and universally regarded as unbeatable. Clay was installed as an 8-1 underdog and dozens of ringside reporters filed pre-written stories about Liston’s victory before the opening bell.
Clay boxed on the outside, moved constantly, and used his speed to make the older, heavier Liston look every one of his years. Liston refused to answer the bell for the seventh round, retiring on his stool with what he later claimed was a shoulder injury. Clay leapt onto the ropes and shouted “I shocked the world” into the ringside cameras. Two days later he announced his conversion to Islam and his new name, Muhammad Ali. Boxing had its most transformational figure.
5. Hasim Rahman KO 5 Lennox Lewis (22 April 2001)
Lennox Lewis was the undisputed heavyweight champion, unified WBC, IBF and IBO belt holder, and looking untouchable after beating Evander Holyfield to consolidate the division. Hasim Rahman was a 20-1 underdog with a modest record and one notable win to his name. Lewis was so confident that he spent his fight camp in South Africa filming a cameo in the Ocean’s Eleven remake and arrived at the venue in Carnival City visibly under-prepared.
Rahman caught Lewis with a single overhand right in the fifth round that dropped the champion flat on his back. Lewis could not beat the count. He had lost the undisputed heavyweight championship on a punch he never saw coming. The rematch in November 2001 saw Lewis reclaim the titles by fourth-round knockout, but the Rahman upset remains one of the biggest single-punch shocks in heavyweight history.
6. George Foreman KO 10 Michael Moorer (5 November 1994)
Twenty years after losing to Ali in Kinshasa, George Foreman completed the greatest comeback in boxing history. Foreman was 45 years old, retired for a decade before returning to the ring in 1987, and challenging the undefeated Michael Moorer for the WBA and IBF heavyweight titles. Moorer was 26 and had just outpointed Evander Holyfield to win the belts. The oddsmakers listed Foreman at 4-1 to win, and few boxing writers gave him more than a puncher’s chance.
Moorer boxed and moved for nine rounds, banking points against a slower, heavier champion who could not cut the ring off. In the tenth Foreman found the range with a short straight right, dropping Moorer flat on his back for the count. At 45 years and 299 days old, Foreman became the oldest heavyweight champion in history, a record that still stands. He was still wearing the same red trunks he had worn against Ali in 1974.
7. Randy Turpin W15 Sugar Ray Robinson (10 July 1951)
British boxing’s greatest ever upset. Sugar Ray Robinson was the pound-for-pound number one on the planet, unbeaten in his previous 91 fights and widely considered the greatest fighter of any era. He arrived at Earl’s Court in London as an overwhelming favourite over Randy Turpin, a 23-year-old middleweight from Leamington Spa with a reputation as a good European-level fighter but no more.
Turpin walked forward for 15 rounds. He outpunched Robinson, outworked him and made the great champion look ordinary for the first time in his career. The judges scored the fight unanimously for Turpin, ending Robinson’s 91-fight unbeaten run and crowning the first British world middleweight champion of the modern era. Robinson reclaimed the title in the rematch 64 days later in New York, but Turpin’s achievement remains one of the finest single nights in British boxing history.
8. Lloyd Honeyghan TKO 6 Donald Curry (27 September 1986)
Another landmark British upset. Donald Curry was the undisputed welterweight champion, holder of the WBA, WBC and IBF belts, and universally regarded as the second-best fighter in the world pound-for-pound behind only Marvin Hagler. Lloyd Honeyghan, a Jamaican-born Bermondsey fighter, was a 5-1 underdog installed as the mandatory challenger with little expectation of victory. Curry arrived at Caesars Palace, Atlantic City, so certain of the win he refused to make weight comfortably. Curry’s orthodox stance and superior reach were supposed to keep Honeyghan at range.
Honeyghan walked forward from the opening bell. He cut Curry over the left eye in the second round, opened another gash on the nose in the third and battered the champion for six one-sided rounds. Curry retired on his stool at the end of the sixth and Honeyghan became the undisputed welterweight champion of the world. British boxing writers called it the greatest away victory by a British fighter in the modern era.
9. Evander Holyfield TKO 11 Mike Tyson (9 November 1996)
Six years after losing to Buster Douglas, Mike Tyson had rebuilt his career and reclaimed the WBA heavyweight title. Evander Holyfield was a former three-time champion who had lost two of his previous four fights and was widely considered to be finished. Tyson entered the MGM Grand as a 25-1 favourite and the fight was universally billed as a Tyson tune-up.
Holyfield outboxed Tyson from the opening bell, using his jab and lateral movement to keep the shorter champion off balance. He dropped Tyson in the sixth round with a left hook, absorbed everything Tyson had left in the second half of the fight, and forced referee Mitch Halpern to stop the contest in the 11th round. The first Holyfield-Tyson fight remains one of the most respected wins in heavyweight history and set up the notorious rematch seven months later, remembered for a different reason entirely.
10. Antonio Tarver KO 2 Roy Jones Jr (15 May 2004)
Roy Jones Jr had spent the previous decade as the consensus pound-for-pound number one in boxing. He was undefeated at world level, had briefly held the WBA heavyweight title after moving up two divisions, and was widely regarded as the most naturally gifted fighter of his generation. Antonio Tarver had lost their first fight by controversial majority decision six months earlier and was a 3-1 underdog for the rematch.
Tarver landed one of the most iconic single punches of the modern era. A short straight left hand in the second round dropped Jones flat, ending the fight and ending the Jones Jr mystique in a single moment. It was the first time Roy Jones Jr had been stopped in his professional career, and the fight is still studied today as a case study in how judges score a champion who has lost half a step against a live underdog.
What Makes a Boxing Upset Great?
The greatest boxing upsets share three ingredients. A dominant, seemingly untouchable champion at the peak of his powers. An underdog written off before the opening bell. And a moment of clarity in the fight where the roles reverse and the sport tilts on its axis. Every upset on this list changed the trajectory of at least two careers, and several of them changed the entire weight division they took place in.
The pattern is almost always the same. The favourite arrives overconfident, under-prepared or distracted by what he expects to be a straightforward night’s work. The underdog arrives with nothing to lose and a specific plan for the fight. And somewhere between the first bell and the last, the underdog finds a moment of belief, and the favourite finds none. It happened to Tyson in Tokyo, to Joshua in New York and to Lewis in Carnival City. It will happen again.
The lesson for boxing bettors is simple. The moneyline favourite is not always the smart bet, and Method of Victory markets often deliver longer odds than the outright win price for the underdog. On the biggest nights in boxing, the ring can be the loneliest 20 feet in sport, and the fighter who walks in with nothing to lose can walk out with everything. Douglas cashed at 42-1. Ruiz cashed at 25-1. Every one of those tickets is now a piece of boxing history.
Further Reading
For more boxing analysis ahead of the next big fight night, read our guide to how boxing scoring works, boxing stances explained and boxing weight classes explained. For heavyweight action this summer, see our full preview of Tyson Fury versus Mariusz Wach on 24 July in Pattaya.
