He holds notable victories over Ernesto Hoost (twice), Francisco Filho, Mark Hunt (three times), Sam Greco, Mike Bernardo (twice), Peter Aerts, Rick Roufus, Remy Bonjasky, Tyrone Spong, Stefan Leko (twice), Masaaki Satake, Maurice Smith, Gary Goodridge (twice), Musashi (twice), Cyril Abidi and Choi Hong-man (twice).

When he was fourteen, Bruce Lee's Fist of Fury influenced him so much that he became interested in striking instead and started trying to incorporate the techniques of Jeet Kune Do he had seen in the film.

At sixteen however he started practising kyokushin, while Jeet Kune Do gave him the southpaw stance which he has maintained throughout his career, even though he is right-handed.

Two months later, on May 4, 1995, he made his first K-1 World Grand Prix appearance in Tokyo, Japan, knocking out both Masaaki Satake and Mike Bernardo, before losing to Peter Aerts in the tournament finals.

On June 1, 1996, in Paris, Le Banner won the ISKA Muay Thai World Super Heavyweight Championship against Curtis Schuster.

Le Banner beat Espedito da Silva via first-round knockout by high kick, to become WKN Muay Thai world super heavyweight champion.

On December 5, at the Tokyo Dome, K-1 Grand Prix '99 final round, Le Banner fought against three-time defending K-1 GP champion Peter Aerts in the quarter-final.

On April 23, 2000, at K-1 The Millennium, Le Banner fought against Kyokushin World Open Karate Tournament 1999 champion Francisco Filho.

On July 30, Le Banner beat Mark Hunt, Nicholas Pettas and Ernesto Hoost, to become K-1 World Grand Prix 2000 in Nagoya tournament Champion.

After this event, Japanese combat sports magazine SRS-DX published a picture of the moment Hunt hit Le Banner's face with an elbow; however, this didn't change the match's result into disqualification.

Le Banner was able to recover and returned to the ring six months later in K-1 Paris 2003, winning the fight by punch combinations over Belarusian Vitali Akhramenko.

[5][6] On December 2, 2006, after his loss against Semmy Schilt at K-1 World Grand Prix 2006 finals, Le Banner announced he was considering his semi retirement from tournament fighting, restricting future appearances to K-1's Superfight events.

[7] On December 8, 2007, in the ninth K-1 World GP appearance of his career, Le Banner defeated Choi Hong-man in the quarter-finals by unanimous decision before facing the reigning K-1 champion Semmy Schilt in the semis.

In the beginning of the second round Schilt landed a low kick that seemed to hurt Le Banner's right knee, on which he had surgery in early 2007.

The fight was eventually stopped by Le Banner's corner throwing the towel to avoid further damage to the injured knee.

At the finals Jerome lost by TKO to the eventual champion Remy Bonjasky when the previously broken left arm was troubling him again.

Le Banner fought Summer Olympic Games 2008 Judo Gold medalist Satoshi Ishii in a mixed martial arts rules bout at DREAM's Dynamite!!

On June 11, at the 8ème Nuit des Sports de Combat in Geneva, he faced for the second time the German Stefan Leko and won by unanimous decision to become the I.S.K.A.

To end the year, he fought for the first time in Pattaya, Thailand, on December 30, for the World Pro League Super Heavyweight title.

In parallel, he fought a Pro Wrestling charity match for victims of 2011 Tōhoku earthquake and tsunami and Fukushima Daiichi nuclear disaster at Inoki Genome Federation.

[9] He won his six fights in Pro Wrestling by (T)KO against Shinichi Suzukawa, Erik Hammer, Kazuyuki Fujita, Montanha Silva, Josh Barnett and Tim Sylvia.

[13][14] Le Banner defeated Roman Kleibl via TKO due to a broken arm in round two of their contest at Time Fight 3 in Tours, France on June 15, 2013.

[17] He was set to fight Sergei Kharitonov at Glory 10: Los Angeles – 2013 85kg Slam in Ontario, California, United States on September 28, 2013[18] but withdrew after suffering a neck injury.

[19] Le Banner knocked out Zinedine Hameur-Lain in round two at La 20ème Nuit des Champions in Marseille, France on November 23, 2013.

[23] He beat Lucian Danilencu via second-round KO at Final Fight – Retour aux sources in Le Havre, France on May 30, 2014.

Le Banner returned at Mixed Martial Arts Grand Prix: The Last of Kings on June 4, 2022, to face Ivan Vičić in a MMA bout.