Unbeatable in the Ring: Top 12 Undefeated Boxing Champions


Remaining undefeated over a long boxing career is a very difficult feat, and the 0 on the record is seen as a precious asset. However, what’s even more impressive is winning a world championship and retiring with that 0.

And to understand exactly how difficult it is, you should know that only 15 of the thousands of world champions across all divisions throughout history have achieved this legendary feat.

Today we will take a look at 12 of those great men who reached the highest peak in boxing and managed to climb down the mountain on their own terms, retiring undefeated. 

12. Jack McAuliffe

Record: 28-0-10

Division: Lightweight

Career: 1884-1897

To begin our list of legendary undefeated world champions, we will travel way back to the 19th century and the bare-knuckle era. The Irish-American boxer Jack McAuliffe was nicknamed “The Napoleon of the Ring“, who was the first man to hold the world lightweight championship by stopping the Canadian Harry Gilmore in 1887 in a fight that lasted 1 hour and 51 minutes.

McAuliffe fought at a time when boxing was still in its infancy, not to mention the quality and accuracy of the official records, so we cannot be 100% sure about the exact records. It was also a time when draws were much more common because oftentimes the agreement was if both men were standing at the end of the bout, it was declared a draw regardless of the scores. Nonetheless, some of his most notable fights were widely publicized, such as the incredible 64-round draw with Bill Myer in 1889.

Boxers’ exploits in the bare-knuckle era are hard to compare to the more modern and organized form of boxing. But this does not change the fact Jack McAuliffe was a world champion and retired undefeated, making him one of only a few to accomplish this legendary feat.

11. Jimmy Barry

Record: 59-0-10

Division: Lightweight

Career: 1891-1899

Sticking to the 19th century we will take a look at Jimmy Barry. The Little Tiger is best known for his bantamweight championship run, but he also held titles in other weight classes. His first title came after the 5ft 2 Barry knocked out Jack Levy for the 100-pound title, though this was not a sanctioned fight.

Barry won his first legitimate USA bantamweight title (102 lbs at the time) in 1894 when he knocked out Jimmy Gorman in 11 rounds. His fiercest rival became Caper Leon. The two shared the ring five times, and after Barry knocked him out in the first match, the next four matches ended with three draws and one no-contest.

Barry went to England in 1897 to face British champion Walter Croot in a fight that would determine who was the undisputed world bantamweight champion. The Little Tiger was successful, knocking out Croot in 20 rounds. But the Brit died as a result of injuries sustained during the fight.

Barry was never the same fighter after that. He fought for another two years without scoring another knockout. His final seven fights all ended in draws, allowing him to retire undefeated. 

10. Kim Ji-won


Division: Super Bantamweight


Scaling the highest peak in boxing and retiring without a loss is something done by a handful of fighters, and one of them is the Korean Kim-Ji Won. The South Korean had a shorter career than most here, but in the four years he was a professional, he won 16 fights and defended the IBF Super bantamweight title four times.

Kim started making a name for himself in boxing by his late teens, but his most significant international success as an amateur came when he was crowned the 1980 Asian Champion. Unfortunately, he did not have a go at the 1980 Olympics because South Korea boycotted the games held in Moscow.

Turning pro in 1982, Kim Ji-won was very active, and by the end of his second pro year, he was the OPBF super bantamweight champion. Kim won his first few fights on points, but once he adjusted to the professional ranks and discovered his power, he began to rack up knockouts. His first major success was the 10th-round knockout of the reigning IBF champion Suh Sung-in and in the next two years, Kim defended his title 4 times scoring 3 knockouts and riding on to the sunset undefeated. 

9. Harry Simon

Record: 31-0

Division: Middleweight/Light heavyweight

Career: 1994-2018

Harry Simon is as famous as being an undefeated two-weight world champion as he is for his problems outside the ring. The Terminator became a professional after representing Namibia as an amateur and competed at the 1992 Olympics in Barcelona.

Simon turned professional in 1994, and after a string of knockouts in Africa, he was brought to the UK, where he spent a year and a half fighting and training at the Peacock Gym in East London. Then his popularity exploded with a victory over the 38-1 Winky Wright for the WBO super-middleweight title.

Simon rose to further prominence after ruthlessly disposing of several challengers and eventually defeating Armand Krajnc for the WBO middleweight title. But then disaster happened and he was involved in a crash that changed his life forever. Harry suffered severe injuries, while three people, including a baby, were killed in the crash.

Simon came back for one fight in 2007 before he was scented to prison for the crash for nearly two years. Despite that, he mounted another comeback, and after dealing with journeymen opposition, he capped his career by appearing on the same card with his son in 2018 and retiring as an undefeated former world champion. 

8. Edwin Valero 

Record: 27-0

Division: Super Featherweight/Lightweight

Career: 2002-2010

One of the most tragic stories in boxing is that of Edwin Valero. The same qualities that instilled fear in his opposition and enabled Valero to achieve his goals were also the ones that ended his life.

The two-division weight champion from Venezuela possessed a madness rarely found in professional fighters. His style was pure aggression, and he bombarded opponents until they fell. In 2006, The Liquidator set a new world record by winning his first 18 fights by knockout.

The southpaw fought with rage every time he stepped inside the ring, and his first world title came in 2006 in a 10-round slugfest against Vicente Mosquera. His heavy blows defeated four more opponents in title defenses. Before Valero decided to step up in weight and challenge for the WBC lightweight title.

In his trademark fashion, ‘El Dinamita‘ destroyed Antonio Pitalúa in two rounds and became a two-division champion. His last two fights were just as successful, but then one of the greatest tragedies in boxing struck. Valero fully succumbed to his madness and stabbed his wife to death in a hotel room in 2010, and the day after he was sent to jail, he hung himself in the cell.

Aside from being one of the few undefeated boxing world champions, Edwin Valero is the only WBC boxing champion to have won every fight by knockout in his career. 

7. Dmitry Pirog

Dmitry Pirog

Record: 20-0

Division: Middleweight

Career: 2005-2012

The Grandmaster, Dmitry Pirog held the WBO middleweight title from 2010 to 2012. Before his career was cut short due to a debilitating back injury.

His nickname was earned because, as a kid, he was a keen chess player and regularly participated in tournaments. This approach was also evident in his boxing. He seamlessly switched between offense and defense and possessed excellent balance and a high ring IQ. Pirog developed his expert use of the shoulder roll after studying tapes of Sugar Ray Leonard and Floyd Mayweather.

After a successful climb in the middleweight rankings fighting mainly in Russia, Pirog announced himself to the wider public when he went to America to face then-unbeaten and highly-rated Daniel Jacobs. Pirog won the WBO middleweight title with a picture-perfect right hand using the shift technique in the fifth round of an entertaining and competitive fight.

Pirog’s reign was briefer than it could have been. After three consecutive defenses in Russia, he was supposed to face Gennady Golovkin. But a ruptured disk first delayed the fight, then completely ended his career before he could realize his full potential, but not before he would become an undefeated world champion.

6. Andre Ward

Record: 32-0

Division: Super Middleweight/Light Heavyweight


Andre Ward was a true pugilist and a wonder to watch for all hardcore boxing fans. Ward was a two-division world champion who was regarded as the best pound-for-pound boxer on the planet during his light heavyweight reign in 2016 and 2017.

His stardom was reached even before he became a pro with a gold medal at the 2004 Athens Olympics. He began his pro career at super middleweight, and his best work came in the highly competitive Super Six World Boxing Classics tournament, where he beat Carl Froch, Mikkel Kessler, and Arthur Abraham, all of whom are former world champions. Before having one last bout at 168 lbs vs Chad Dawson in a convincing display.

His transition to light heavyweight was equally successful, and his two fights with Sergey Kovalev where Ward unified the majority of the light heavyweight titles and will be remembered as classics.

This allowed Andre Ward to win so many accolades and retire undefeated with a fluid and adaptive boxing style, capable of defeating any threat. Ward, a left-handed fighter fighting from an orthodox stance, relied heavily on his lead right hand to both control the distance and do damage.

Ward was able to incorporate a variety of styles into his game making him a favorite among those who prefer the most subtle and technical aspects of the sweet science. 

5. Sven Ottke

Record: 34-0

Division: Super Middleweight/Light Heavyweight

Career: 1997-2004

Sven Ottke is a name rarely heard in the boxing world, despite the fact he was a long-reigning title holder who retired undefeated with 34 victories. The Phantom had a long and successful amateur career, fighting 300 times and winning 256 of them.

Ottke turned professional at the age of 30, and within a year he defeated Charles Brewer for the IBF super-middleweight title. What followed was one of the longest title reigns in boxing history, with 21 defenses (a record for the division tied with Joe Calzaghe). In 2003, Ottke also won the WBA belt from Byron Mitchel and defended it five times before he stepped down undefeated in 2004.

Sven Ottke was a durable fighter who wore down his opponents and won most of his fights by decision. Furthermore, he refused to fight outside of Germany, which has been cited as a major reason for his undefeated record. Nevertheless, the fact remains, Ottke, was still a long-reigning world champion who retired without tasting defeat as a professional. 

4. Joe Calzaghe 

Record: 46-0

Division: Super Middleweight/Light Heavyweight


Joe Calzaghe is sometimes considered the best super middleweight of all time and held the WBO title for more than ten years defending it 21 times, a record that still stands. The Pride of Wales was the first boxer to unify three of the major belts in the four-belt era and is often regarded as the best European boxer to ever step in the ring.

Calzaghe began his 15-year professional career in 1993 and went undefeated in 46 fights. His historic title reign began in 1997 when he faced fellow British boxing legend, Chris Eubank.

Despite his long reign, Calzaghe’s most notable wins came later in his career. His most recent super middleweight title defense was a unanimous decision victory over Mikkel Kessler in 2007. Before he moved up in weight to fight and defeat fellow Hall of Famers Bernard Hopkins and Roy Jones Jr.

The Italian Dragon, Joe Calzaghe, had a truly unique boxing style. His biggest trait was his never-failing engine, which allowed him to never stop punching. Then he did so in varying rhythms and from awkward angles that left opponents dazzled. Add to that the ability to adapt and perform under extreme pressure, and it’s easy to see why Calzaghe is regarded as one of the best to ever do it. 

3. Ricardo Lopez

Record: 51-0-1

Division: Mini Flyweight/Light Flyweight

Career: 1985-2001

Few if any boxers can claim to be as flawless as Ricardo Lopez. The Mexican ruled over the mini flyweight division with record-breaking 21 title defenses from 1990 until 1998, when he climbed up and conquered the IBF junior flyweight title, with which he retired. 

Before embarking on his unbeatable 51-fight professional win streak, Ricardo Lopez was an amateur for 3 years and did not taste defeat even once. He is in fact the only world champion boxer to have retired undefeated both as an amateur and as a professional. The only dent on his record was a single draw against Rosendo Alvarez, avenged in a rematch 8 months later.

Lopez’s style is best described by the term “technical perfection.” He just had no weak spots, neither on offense nor in defense. Lopez had a razor-sharp jab, precise and intricate footwork, and all-around incredible skills. He was a master at tagging the opponents from a distance and then moving away. When they did manage to close the range, they just found out Lopez is just as good on the inside.

And on top of his technical prowess, Lopez had power unbefitting a 105-pound fighter. The result of this combination is clear though. An undefeated amateur and professional record, a record-breaking world title run, and a 75% knockout ratio at mini flyweight.  

2. Rocky Marciano

Record: 49-0

Division: Heavyweight

Career: 1947-1955

Rocky Marciano is considered one of the greatest heavyweights and is the only world champion in the division to have retired undefeated. Despite his small stature for a heavyweight, The Brockton Blockbuster has a career knockout ratio of 87.8%, one of the highest in heavyweight boxing.

Rocky began boxing professionally in 1948 and knocked out his first 16 opponents, nine of whom were knocked out in the first round. He challenged for the heavyweight crown against then 38-year-old, Jersey Joe Walcott, who managed to build a lead on the scorecards but was brutally knocked out by Marciano in the 13th.

Rocky defended his title six times in the span of two years, beating Roland La Starza, Ezzard Charles, Don Cokell, and finally Archie Mooer before retiring.

Aside from his undefeated record, Marciano will be remembered for his ferociousness, endurance, and brutal knockouts. Being a small heavyweight even by the standards of his days and with shorter than-usual hands. Marciano made the best use of his frame and perfected a style to match it.

He hit as hard as he could and often missed, but when his punches landed, they did som serious damage. He expertly closed the distance and then bulldozed the opponents until they could stand no longer.  

1. Floyd Mayweather Jr

Floyd Mayweather fighter of the decade

Record: 50-0

Division: Five different weight classes

Career: 1996-2017

One of the best ever and the latest champion to retire with a perfect record is Floyd Mayweather Jr. Not only was he a world champion, but he won 15 major world titles in five different weight classes, from super featherweight all the way up to light middleweight.

It will be hard to list all of Mayweather’s accomplishments in such a short format. Floyd grabbed his first title back in 1998 when he defeated Genaro Hernandez for the WBC super featherweight title.  He then conquered the titles at super lightweight, lightweight, and even light middleweight by defeating Oscar De La Hoya, Miguel Cotto, and Canelo Alvarez. But his best work was done at welterweight, where he outclassed fighters like Manny Pacquiao, Robert Guerrero, Ricky Hatton, and Zab Judah.

Despite what you may think of Mayweather outside of the ring, once the bell rang, he was one of the finest boxers in history, some may even claim he was the best. Where Floyd shined the most was in his defense and counterattacking skills. Improving and perfecting the Philly shell into something unique. Mayweather was able to deal with everything coming his way.

In many cases, he had trouble early in the fight, but every single time he found a way to overcome it and win convincingly.

Much can be said about Floyd Mayweather’s career and when he chose to meet his biggest rivals. But the fact is he was a defensive genius who conquered every division he fought in and retired with a perfect 50-0 record and 16 shining belts in his showcase.

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Plamen Kostov

I am Plamen, and I have been involved in martial arts for 15 years, writing about them for the last 2. I am fascinated by all aspects of fighting, be it physical, mental, or philosophical. The sweet science of boxing has a special place in the pantheon of combat sports and in my heart, and I will be sharing my knowledge, analysis, and opinions on it here on "Boxing Life"

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