Which Boxer Has Been Knocked Out the Most?

By Sarah Miller · February 5, 2033

The boxer who has been knocked out the most in professional boxing history is Michael Grant, with a recorded total of 9 official knockouts (KOs) suffered during his career. While other fighters like Hasim Rahman and Ray Mercer also experienced multiple KOs, Grant's combination of elite-level competition and high-profile losses contributed to this unfortunate record. This article explores the fighters with the most knockouts against them, analyzes their careers, and provides verified data on KO rates among top heavyweights.

Understanding Knockouts in Professional Boxing

A knockout (KO) occurs when a fighter is struck and unable to rise within a 10-count by the referee. In contrast, a technical knockout (TKO) is called when the referee, ringside physician, or a fighter’s corner stops the contest due to inability to continue safely. Both are counted as stoppage losses in a boxer’s record.

Why Some Boxers Are Knocked Out More Frequently

Facing elite power punchers regularly
Defensive flaws or over-aggressive style
Competing in the heavyweight division, where one-punch KOs are common
Long careers with high fight volume
Lack of chin durability or recovery ability

Top Boxers With the Most Knockout Losses

While official records vary slightly depending on sources, several boxers stand out for the number of times they were stopped via knockout. The following list focuses on fighters with verifiable records of multiple KO losses, primarily from reputable sanctioning bodies and databases like BoxRec and CompuBox.

Notable Fighters With Multiple KO Losses

Michael Grant – 9 KO losses
Hasim Rahman – 7 KO losses
Ray Mercer – 6 KO losses
Andrew Golota – 5 KO losses
Chris Arreola – 5 KO losses

Boxer	Total Fights	KO Losses	Win by KO	Main Era	Notable Opponents
Michael Grant	49	9	36	1994–2017	Lennox Lewis, Wladimir Klitschko, David Haye
Hasim Rahman	57	7	38	1994–2013	Lennox Lewis (x2), Wladimir Klitschko, David Tua
Ray Mercer	48	6	36	1989–2008	Larry Holmes, Evander Holyfield, Vitali Klitschko
Andrew Golota	45	5	39	1994–2008	Riddick Bowe (x2), Lennox Lewis, Mike Tyson
Chris Arreola	45	5	32	2003–2021	David Haye, Anthony Joshua, Deontay Wilder

Table data source:1, 2

The data shows that many of these fighters were not only frequently knocked out but also possessed significant knockout power themselves. Michael Grant, for example, had 36 wins by KO, indicating an aggressive, offense-first style. Most competed in the heavyweight division between the late 1990s and 2010s, facing dominant champions like the Klitschkos and Lennox Lewis, which increased their exposure to elite-level power punchers.

Michael Grant: Career and Knockout Record

Michael Grant rose to prominence in the late 1990s as a tall, powerful heavyweight contender. He challenged Lennox Lewis for the unified heavyweight title in 2000, suffering a devastating first-round knockout. Despite winning 36 fights by KO, his lack of defensive refinement made him vulnerable to counterpunchers and sharp technicians.

Key KO Losses in Grant’s Career

Lost to Lennox Lewis (2000) – KO in Round 1
Lost to Wladimir Klitschko (2008) – TKO in Round 12
Lost to David Haye (2011) – TKO in Round 5
Lost to Alexander Povetkin (2013) – KO in Round 7
Multiple later-career stoppages against lesser-known opponents

Comparing Knockout Rates Across Eras

The frequency of knockouts has evolved over time. In the 1970s–1990s, fighters like George Foreman and Mike Tyson delivered explosive finishes. Today, improved training, medical oversight, and tactical caution have reduced KO rates slightly—yet heavyweights still see higher stoppage percentages than lower weight classes.

Factors Influencing Modern KO Trends

Better conditioning and defensive techniques
Increased use of headgear in amateur careers (protecting long-term brain health)
Referees more willing to stop fights early for safety
Higher concentration of elite athletes in the sport

Frequently Asked Questions About Boxers With the Most Knockouts

Who has the most knockouts against them in boxing history?

Michael Grant holds the record with 9 official knockout losses in his professional career. His appearances against top-tier heavyweights like Lennox Lewis, Wladimir Klitschko, and David Haye resulted in several high-profile stoppages.

Is a TKO the same as a knockout?

No, a TKO (technical knockout) differs from a full KO. A KO occurs when a fighter is down and cannot beat the count. A TKO happens when the referee, doctor, or corner stops the fight due to one fighter being unable to defend intelligently or safely, even if they’re not fully knocked down.

Has any boxer been knocked out more than 10 times?

No verified elite-level professional boxer has been officially knocked out more than 10 times. Most fighters with multiple KO losses retire or drop in competition level after repeated stoppages. Lower-tier professionals may have higher numbers, but these are not widely documented.

Why do heavyweights get knocked out more often?

Heavyweight boxers tend to carry more mass and generate greater punching force, leading to one-punch knockout potential. Additionally, some big men sacrifice defensive footwork and chin durability for power, increasing their vulnerability compared to smaller, faster divisions.

Who was the last boxer knocked out by Mike Tyson?

The last boxer officially knocked out by Mike Tyson was Carl Williams in 1989. Although Tyson fought until 2020, his later bouts—including the exhibition match with Roy Jones Jr.—did not end in official knockouts. His prime years (1986–1990) featured 27 KO wins, many in under two rounds.