In December 2012, Juan Manuel Marquez finally landed the punch he had spent 10 years and three-and-a-half fights looking for. With a single second remaining in Round 6 of their fourth fight, he put Manny Pacquiao to sleep.
The knockout is the single most exciting moment in sports. Only the walk-off homer in baseball can compare.
Boom and it's all over, with the fans left to catch their breath.
I've tried to balance between sudden drama, pure aesthetics and historical significance for this list. My own bias as a writer and historian has led me to come down most heavily on significance.
In August 2010, this fight made Giovani Segura a rising star. The reigning WBA light flyweight champ faced off with undefeated WBO champion Ivan Calderon.
Calderon was an excellent technical boxer, but Segura's physical advantages were overwhelming. His edge in reach allowed him to unload on Calderon from long range with wide, sweeping hooks and uppercuts.
It was an exciting fight most of the way, with Calderon largely holding his own, but by Round 8, Segura was up on all three cards. Once he was in the lead in the fight, he upped his aggression and pressed hard for the finish.
Segura drove Calderon into the corner and finished him with a jolting uppercut.
This was Shane Mosley's comeback fight in September 2008 after losing to Miguel Cotto the previous year. Mosley was definitely on the downside of his career by this point, but he was still far too good of a matador for Ricardo Mayorga's charging bull.
Mayorga provided an exciting fight, but Mosley led on two of three cards when he landed a series of big punches in the final round. Sensing the opening to finish, Mosley attacked and unloaded a brutal barrage to drop Mayorga for an eight-count.
As soon as Mayorga was back on his feet, Mosley dropped him again with a single hook, knocking him out with one second remaining in the fight.
Abner Mares came into this fight in August 2013 viewed as one of the sport's emerging pound-for-pound stars. He was an undefeated, three-division world champion.
Jhonny Gonzalez was a well-respected former champion, but the boxing media largely wrote about him as if he were merely an opponent in the buildup.
Instead, he demonstrated that he remains a world championship-caliber fighter. He blitzed Mares, making him appear undersized in the featherweight division.
This is one of the key knockouts that built Nonito Donaire's legend. In February 2011, he faced highly regarded WBA and WBO bantamweight champion Fernando Montiel, looking to become a three-division world champion.
Donaire showed signs of finding the range on his lead hook early in the fight, and in the second round, he landed a smashing shot. Montiel dropped hard to the canvas with his legs twitching.
Amazingly, Montiel managed to get back to his feet, and the fight was allowed to briefly continue.
Amazingly, this is the second fight from last year that makes its way onto this list. I consider that further proof that last year really was the best year in boxing of the past two decades.
Adonis Stevenson seemed to come out of nowhere when he demolished WBC and lineal light heavyweight champion Chad Dawson in Round 1 last June. People knew he could punch, but Dawson was a highly regarded, well-rounded champion.
Stevenson landed a monster punch early in the first, and that was all it took. On the year, Stevenson recorded four KOs in 2013.
This thrilling knockout was The Ring magazine's KO of the year for 2009. It was the most spectacular shot of Manny Pacquiao's remarkable career.
But I only have it rated at No. 5, and I am aware that certain Manny Pacquiao fans think he should be rated first on every single list he appears on. So I will point out that Pacquiao was expected to stop Ricky Hatton, just as Floyd Mayweather had already done.
Still, it was easily one of the best knockouts of the past 10 years.
Many boxing fans, especially those too young to remember Thomas Hearns vs. Marvin Hagler or Joe Frazier and Muhammad Ali, will tell you this fight from May 2005 is the greatest of all time.
Both of Diego Corrales' eyes were swollen badly as Round 10 began. Early in the round, Jose Luis Castillo dropped him to the canvas.
Castillo dropped Corrales a second time, and then Corrales lost a third point for excessive spitting out of his mouthpiece.
Then Corrales landed a perfect hook that stunned Castillo. Corrales trapped Castillo on the ropes and unloaded. Castillo was caught upright and unconscious when the referee halted the action.
This fight in November 2010, coming seven months after Sergio Martinez's defeat of Kelly Pavlik, confirmed Maravilla's status as a pound-for-pound star. In terms of pure aesthetics, it might be the top knockout on this list.
In Round 2, Paul Williams and Martinez both threw left hands at the same time, and Martinez's got there a half-beat quicker. Williams was out cold the moment the glove touched him.
This kind of explosive power is what made Martinez one of the special fighters of the past decade.
This knockout in May 2004 marked the end of an era. Roy Jones Jr. had been the pound-for-pound king for nearly a decade when he barely survived Antonio Tarver with a majority decision in 2003.
In the rematch, Tarver landed a perfect right hook on a leaning-back Jones in Round 2 that knocked him flat. Jones somehow beat the count, but the referee quickly waved off the action.
Jones has never been the same fighter since, though he has never gone away. He still appears to be looking for fights a decade later.
When Juan Manuel Marquez knocked out Manny Pacquiao in December 2012, it finally brought a definitive conclusion to the closest and most important boxing rivalry of the past decade.
In terms of a knockout, it had everything you could ask for. In addition to the previously mentioned significance, it represented a thrilling swing in momentum, as Pacquiao had been in control of the fight up to getting caught.
In terms of aesthetics, it was a thing of beauty. Marquez, the counterpunching artist, landed his masterpiece.