1. Francis Ngannou
The terrifying, amazing Ngannou finishes in the top spot. I personally had him second only to previously discussed Prochazka. Like Prochazka, Ngannou is the only other fighter in MMA history who can generate power from the most unorthodox of angles. Blows that from other fighters wouldn't hurt much at all turn into insane, vicious knockouts at the hands of Ngannou. His speed for a large heavyweight is dizzying, and he has true knockout power in both fists. And not just knockout power, but the most brutal, concussive one-punch knockout power. Ngannou is most known for his punches, but his bone-crunching leg kicks are among the most powerful I've ever seen at heavyweight. They practically crippled Junior dos Santos inside of a minute, setting up the knockout sequence, among other examples. Statistically, Ngannou is only in the middle of the pack for our top 10 when it comes to knockout rate. He has 12 KOs in 17 victories, for a 71% rate. However, that overlooks a vital detail. Ngannou became a professional mixed martial artist very late in life, with his first fight occurring when he was already 27. A number of his early pre-UFC fights ended with Ngannou winning by submission (!) and it wasn't until his early to mid-30s that Ngannou achieved his peak. But once he did, the question became not whether opponents could defeat Ngannou, or even survive, but whether they could last more than two minutes against him. On his way to his first title shot, Ngannou already demonstrated impressive results. He caused a doctor's stoppage of highly skilled Curtis Blaydes after the second round due to a closed eye, massacred Bohan Mihajlovic with a swarm of punches in 94 seconds, lowered that to 92 seconds in a slaughter of Andrei Arlovski, and then scored one of the most eye-popping knockouts ever of Alistair Overeem in 102 seconds. Remember what I mentioned about producing power from unorthodox angles? As Overeem was bobbing and weaving, thinking that he had dodged all of Ngannou's powerful blows, the Cameroonian quickly recovered and from nowhere, threw a murderous uppercut that collided with Overeem's chin and appeared to launch his head into the stratosphere.
After a humbling defeat at the hands of Stipe Miocic and a horrible eyesore decision loss against fellow knockout artist Derrick Lewis, many were counting Ngannou out. In a rematch against the very same Blaydes, now an elite title contender himself, Ngannou found himself a big underdog. But unbeknownst to most, Ngannou was still improving. He proved that by needing just 45 seconds to dispose of Blaydes. Facing returning heavyweight legend Cain Velasquez, a man many considered the greatest heavyweight ever, Blaydes sent him into retirement and pro wrestling with a 26-second demolition. Adding to his list of all-time great, world champion victims, Ngannou clobbered dos Santos in 71 seconds. Undefeated fellow knockout artist Jairzinho Rozenstruik, a man who just taken off a large portion of Overeem's lips with his punches, was seen as a stern test, especially since he possessed a granite chin. There were also worries that Ngannou would conduct the fight in the same passive manner he had against Lewis. Showing that he was a completely different martial artist now, Ngannou charged forward seconds into the fight, eating a big Rozenstruik strike but reacting as if it was no more than a fly, splattering the Surinamese sensation with a brain-busting left hook followed by a killer overhand right, leaving Rozenstruik an unconscious mess against the fence. When Ngannou rematched Miocic for the world title, the same man who had beaten him so thoroughly, he further demonstrated his growth as a fighter, wisely pacing himself before obliterating Miocic with a left hook early in Round 2. Having left the UFC as the heavyweight champion and still likely in his prime, MMA fans, myself included, are curious when and where Ngannou will fight next. But one thing is for certain; he has already established a legacy as arguably the heaviest hitter in the sport's history.