The Greatest Upsets in Boxing History

5 June 2025

Boxing is full of twists and turns, but nothing captivates fans more than an underdog defying the odds. Some of these upsets are so shocking that they leave commentators speechless, sportsbooks trembling, and fans questioning everything they thought they knew about the sport.

But what makes an upset so special? It’s not just about winning—it’s about proving the doubters wrong, rewriting history, and showing the heart of a true fighter. From jaw-dropping knockouts to tactical masterclasses, let's take a deep dive into some of the most unforgettable upsets in boxing history.

1. Buster Douglas Stuns Mike Tyson (1990)

Let’s be honest—no one saw this coming. Mike Tyson was an absolute wrecking machine in the late 1980s. He was undefeated, the undisputed heavyweight champion, and viewed as nearly invincible. Then came James “Buster” Douglas, a 42-to-1 underdog, stepping into the Tokyo Dome on February 11, 1990.

For the first few rounds, Douglas held his own, using his jab to keep Tyson at bay. But when Tyson knocked him down in the eighth round, it seemed like the inevitable had arrived. Only, Douglas got up. And not only did he recover, but he fought back with a fire no one expected.

In the tenth round, Douglas delivered a crushing uppercut followed by a furious combination that sent Tyson to the canvas—for the first time in his career. The champ couldn’t beat the count. Just like that, the most dominant fighter in the world had been dethroned.

A shocking upset? Absolutely. But more importantly, it was a reminder that in boxing, nothing is guaranteed.

2. Muhammad Ali Shakes the World Against Sonny Liston (1964)

Before he was “The Greatest,” Muhammad Ali (then Cassius Clay) was just another loud rookie who nobody thought had a shot against Sonny Liston. Liston was a terrifying heavyweight champion, a man whose punches left opponents broken—both physically and mentally.

Coming into their fight on February 25, 1964, Liston had demolished Floyd Patterson twice in the first round. Most experts believed Ali wouldn’t make it past the third. But Ali had different plans.

From the opening bell, Ali’s speed and movement frustrated Liston. By the sixth round, Liston had taken a beating, and whether it was from injury or pure frustration, he quit on his stool before the seventh. Just like that, a brash young fighter who promised to "shock the world" had done exactly that.

This wasn’t just an upset—it was the birth of an icon.

3. Hasim Rahman Floors Lennox Lewis (2001)

Lennox Lewis wasn’t just a champion—he was the heavyweight king. A dominant force who had beaten the best of his era. Hasim Rahman? He was supposed to be just another name on Lewis’ resume.

When they met on April 22, 2001, Lewis was already looking ahead to bigger fights, even filming a movie in the weeks leading up to the bout. Rahman, on the other hand, came in focused and determined.

In the fifth round, Rahman landed a thunderous right hand that sent Lewis crashing to the mat. The crowd went silent. Lewis struggled to get up, but the fight was over. The world had a new heavyweight champion, and no one saw it coming.

This fight was a perfect example of why you can never overlook an opponent in boxing. One punch can change everything.

4. Andy Ruiz Jr. Shocks Anthony Joshua (2019)

Talk about unexpected. Andy Ruiz Jr. wasn’t even supposed to fight Anthony Joshua—he was a late replacement for Jarrell Miller, who failed a drug test. And let’s be honest, when people saw Ruiz’s soft physique, they didn’t give him a shot against the chiseled, athletic Joshua.

But what Ruiz lacked in appearance, he made up for in skill and heart. On June 1, 2019, inside Madison Square Garden, he turned the boxing world upside down.

Joshua started strong, even knocking down Ruiz in the third round. But instead of folding, Ruiz roared back—dropping Joshua twice in the same round. By the seventh, after two more knockdowns, the ref stopped the fight.

Just like that, Andy Ruiz Jr., a fighter few had taken seriously, had become the first Mexican heavyweight champion in history.

This was proof that boxing isn’t won by looks or hype—it’s won in the ring.

5. Corrie Sanders Blasts Wladimir Klitschko (2003)

Wladimir Klitschko was supposed to be the future of heavyweight boxing. He had the size, the power, and the skill to dominate for years. Corrie Sanders? He was a 37-year-old part-time golfer who most thought was way past his prime.

When they met on March 8, 2003, Klitschko was heavily favored. He had youth, athleticism, and championship aspirations. But Sanders had something else—an incredibly fast left hand.

Right from the start, Sanders hurt Klitschko with his speed and accuracy. By the second round, Klitschko had been knocked down four times. The fight ended in a shocking TKO, and Klitschko’s aura of invincibility was shattered.

This loss forced Klitschko to rebuild his career, but at that moment, Corrie Sanders had achieved one of the greatest upsets in heavyweight boxing.

6. Randy Turpin Defeats Sugar Ray Robinson (1951)

Sugar Ray Robinson is widely considered one of the greatest boxers of all time. He was nearly untouchable, boasting a record of 128 wins with just one loss heading into his fight against Randy Turpin on July 10, 1951.

Turpin, a relatively unknown British fighter, wasn’t expected to last against Robinson, let alone beat him. But from the opening bell, Turpin fought with confidence, using his strength and awkward style to frustrate the legendary champion.

After 15 grueling rounds, Turpin won by unanimous decision. The boxing world was in disbelief—Robinson had been bested.

Though Robinson would avenge the loss in their rematch, Turpin’s victory remains one of the greatest upsets in boxing history.

Why Do Boxing Upsets Happen?

What makes these upsets so fascinating? It’s a mix of factors:

- Underestimating the Opponent – Champions sometimes let their guard down, assuming an easy win.
- Styles Make Fights – What works against one opponent might not work against another.
- One Punch Can Change Everything – In boxing, all it takes is one perfectly placed shot.
- Mental Toughness – Some underdogs thrive under pressure, while favorites crack.

That’s what makes this sport so unpredictable. The moment you think you’ve figured it out, boxing reminds you that anything can happen.

Final Thoughts

Boxing history is filled with moments where the unthinkable became reality. These upsets aren’t just shocking; they’re a testament to the unpredictability of the sport and the spirit of the underdog.

That’s the beauty of boxing—on any given night, no matter the odds, a fighter can defy expectations and shock the world. And honestly, isn’t that why we love the sport?