Key Takeaways

• These knockouts showcase how quickly a fight can turn, regardless of who’s ahead on the scorecards.
• Several of the featured KOs became viral moments that defined careers or rivalries.
• The list includes a mix of heavyweight clashes and lower-weight surprises, offering a broad view of boxing’s most dramatic finishes.

A knockout is the one ending in sports that can’t be negotiated. No judges, no “he stole the last two rounds,” no debate about tactics. It’s just the cleanest full stop possible: one fighter still standing, the other trying to remember how gravity got so aggressive. And the wild part is how many different ways a KO can feel “crazy.” Sometimes it’s the punch itself, a perfectly timed counter that looks like it came from a training-room prophecy. Sometimes it’s the stakes, like a rivalry ending in one frozen frame or a belt changing hands in the most ruthless way imaginable. And sometimes it’s the sheer unfairness of it all: a fighter doing everything right for rounds, then getting erased by a single mistake.

For Part 1, I’m leaning into nine finishes that still make fans talk in bold caps. These are the knockouts that instantly became reference points, the ones you see in montages, debates, and “show this to somebody who thinks boxing is boring” arguments. You’ll get a little bit of everything here: one-punch slumps, body-shot agony, heavyweight history flipping mid-fight, and a reminder that in boxing, being “up on the cards” can turn into trivia in about half a second. Part 2 can go deeper with more classics and modern chaos.

1. Deontay Wilder vs. Dominic Breazeale

Some knockouts are dramatic. This one was basically an on/off switch. Wilder stalks, measures, then unloads a monstrous right hand that drops Breazeale flat — the kind of heavyweight finish where the replay somehow looked worse each time because of how clean it landed. The official stoppage came in Round 1, and it’s still one of Wilder’s most replayed “you can’t teach that power” endings.

2. Sergio Martínez vs. Paul Williams II

This was the definition of “instant highlight.” Williams came forward and Martínez threaded a single, nuclear left hand that shut the lights off immediately. No wobble, no delayed fall, just a sudden, face-down finish that made the arena react like it collectively lost signal. The Round 2 end was still one of the cleanest examples of perfect timing meeting perfect placement.

3. George Foreman vs. Michael Moorer

Foreman spent much of the fight giving away rounds, eating shots, and looking like the cards were slipping away. Then he landed one of those “old man strength is real” right hands and Moorer dropped like the game got unplugged. The finish came in Round 10, and it’s historic on top of being brutal: Foreman became heavyweight champion again at 45, the oldest to do it.

4. Roy Jones Jr. vs. Virgil Hill

Head-shot knockouts get all the hype, but this one was proof that body work can be just as savage. In the fourth round, Jones dug a right hand into Hill’s midsection and Hill folded, stuck in that awful space where you want to beat the count, but your body won’t cash the check. It was a rare KO that looked painful in real time.

5. Mike Tyson vs. Trevor Berbick

Peak early Tyson: Pressure, speed, and bad intentions from the opening bell. Berbick got dropped, tried to rise, and his legs basically refused to stay in the same timeline, turning the aftermath into one of boxing’s most replayed visuals. The stoppage came in Round 2, and it was also a landmark moment: Tyson became the youngest heavyweight champion at just 20.

6. Thomas Hearns vs. Roberto Durán

Durán’s toughness was the stuff of legend, which is why this finish still stings to watch. Hearns caught him clean, dropped him, and then closed the show with a follow-up that forced the stoppage. It was quick, sharp, and shocking because it’s Durán on the receiving end of a hard reset. Officially, Hearns got the TKO in Round 2.

7. Hasim Rahman vs. Lennox Lewis I

One of heavyweight boxing’s classic “wait… WHAT?” moments. Lewis was the established champion, expected to handle business, and Rahman detonated a right hand that flipped the entire script. Lewis went down heavy, tried to recover, and... couldn’t. The upset landed in history in the midst of Round 5, the kind of KO that turns the safest prediction into instant comedy.

8. Manny Pacquiao vs. Ricky Hatton

This was a knockout that made people wince before it even landed. Hatton’s aggression was part of his identity, but it also left him open, and Pacquiao punished that with terrifying precision. After earlier knockdowns, the ending arrived with a left hand that put Hatton out cold in Round 2. It was fast, violent, and unforgettable in the way only a one-punch shutdown can be.

9. Julian Jackson vs. Herol Graham

A cruel reminder that boxing doesn’t grade on overall performance, only on moments. Graham was outboxing Jackson and stacking rounds, then Jackson landed one right hand and everything instantly changed. The punch was so final, it felt like the fight just disappeared. Officially, Jackson scored the KO in Round 4, a highlight that still gets brought up anytime someone says “just box smart and you’ll be fine.”

10. Anthony Joshua vs. Jake Paul

The “this can’t be real” factor was baked in, but the ending still landed like a slap. Joshua stayed patient, let Paul burn energy, and then turned the lights out in the sixth with a finishing sequence that left no ambiguity. Officially, it went down as a Round 6 KO in Miami — a crossover spectacle ending in the most traditional way possible: One clean heavyweight shutdown.

11. Canelo Álvarez vs. Amir Khan

This Round 6 takedown was the definition of “everything’s fine… until it’s absolutely not.” Khan’s speed had moments early, but the risk of jumping weight for a bigger puncher was always lurking. Then Canelo delivered a perfectly-timed right hand, and Khan went down out cold — the kind of KO where the replay felt even harsher because the punch was so clean.