Such was the case in 2011's best knockout thus far, Cheick Kongo's first-round finish of Pat Barry on June 26.
With a fight featuring two strikers, many assumed fireworks were likely, but no one could anticipate what was to come. Barry, a powerful striker with hellacious leg kicks, began by tenderizing Kongo's legs. After a feeling-out period, Barry began to open up his offense, blasting Kongo with a right behind the ear. Kongo went down and Barry looked for the finish, landing shots to his grounded opponent.
Kongo looked rubber-legged as he tried to get to his feet, but he managed to do so seconds later. A second time, Barry dropped him, with Kongo's right leg folding behind him as he crashed to the mat. UFC commentator Joe Rogan screamed "He's out," thinking the fight was over.
Rogan couldn't be blamed for his assumption; Kongo was clearly in la-la land, and at one point, referee Dan Miragliotta appeared to step in, ready to stop it. Replays showed that Miragliotta actually put his hands on Barry's shoulders, about to intervene. But just before he waved off the action, something happened. Kongo rose to his knees. Miragliotta backed off and Barry continued the assault he had never stopped.
Finally, Kongo got to his feet, backed up against the cage to steady himself and drilled Barry with a right hook that landed flush against the ear. Barry wobbled but continued moving forward.
With that, Kongo walloped him with a crushing right uppercut. The punch turned Barry's lights out. His body collapsed to the canvas and Kongo instinctively followed him there, landing two academic punches before Mirgaliotta stopped him from further damage.
Just 10 seconds after Rogan had declared the fight over, it was. But instead of Barry in the middle of the cage with his hands raised, it was Kongo.
The fight may lack the significance of a championship bout knockout or even a No. 1 contenders fight. Neither man is close to the top five right about now. But the knockout is an enduring reminder of just how thrilling -- and also how cruel -- mixed martial arts can be.
2. Anderson Silva vs. Vitor Belfort, UFC 126
These two had years of bad blood and bad feelings come to a head at UFC 126, with Silva's UFC middleweight championship on the line. Many people felt that if any divisional striker could match Silva's firepower, it was the heavy-handed Belfort. Instead, what we got was another Silva highlight for the ages. He knocked Belfort down with a rarely used front kick, then finished with a few ground punches to retain his belt.
3. Lyoto Machida vs. Randy Couture, UFC 129
Taking a page out of his teammate Silva's book, Machida closed the final chapter of Couture's career by knocking him unconscious with a crane kick. The blow was so powerful it knocked out one of Couture's teeth.
4. Patricky Pitbull vs. Toby Imada, Bellator 39
Imada made a name for himself in the past with a highlight reel submission, but this time, he was on the receiving end when Pitbull ended things with a spectacular sequence. As Imada waded forward, Pitbull perfectly jumped into a flying knee. Imada somehow stayed on his feet, but his legs were shaky and his senses dulled. Pitbull recognized his opponent was ripe for the picking, and closed out the show with a fight-ending left hook.
5. (tie) John Makdessi vs. Kyle Watson, UFC 129
Makdessi looked on his way to a workmanlike decision over Watson on the undercard of the UFC's biggest ever show when he hit paydirt, connecting on a flashy, one-punch, spinning backlist KO for the finish.
5. (tie) Sam Stout vs. Yves Edwards, UFC 131
The match between Stout and Edwards was expected to be an interesting fight between two battle-hardened veterans, but instead it left us with the takeaway moment of the night. Nearly four minutes into the first round, Stout and Edwards threw hooks at nearly the same time. Stout ate Edwards' shot as he was firing back a left of his own. The blow landed perfectly and Edwards was unconscious before he hit the mat. In an excellent display of sportsmanship, Stout eschewed possible follow-up shots, instead walking away with his hands in the air.