Japan's Pride organization in 2001 marketed Jackson as being a homeless person. Jackson, still a relatively unknown fighter, first was matched at Pride 15 against fellow Wrestler and Japanese superstar Kazushi Sakuraba, who was at that time Pride's most prominent domestic fighter. Jackson lost due to a rear naked choke from Sakuraba. Jackson captivated the Japanese fans with his exciting performance and also gained their respect and admiration for his valiant effort against the much more experienced Sakuraba.
Jackson then went on to defeat Masaaki Satake, Igor Vovchanchyn, Kevin Randleman and Mikhail Illoukhine in successive Pride bouts. He also made forays into kickboxing with a pair of victories over Kickboxer Cyril Abidi, under K-1 rules. The first kickboxing bout between Abidi and Jackson was on July 14, 2002. Many expected Jackson's wild style of striking would not translate into the K-1 ring, thinking he would be outclassed by such a schooled and disciplined striker as Abidi. Instead, Jackson overwhelmed Abidi from the opening bell, and knocked him down less than a minute into the bout. Jackson then scored a hard underhand right to the chin of Abidi, knocking him out only 1:55 into the very first round.
Jackson continued his Pride career with a TKO victory over Ikuhisa Minowa at Pride Shockwave 2003. He then faced Ricardo Arona at Pride Critical Countdown 2004 with the winner to face Wanderlei Silva. Late in the first round Arona caught Jackson in a triangle choke, Jackson immediately picked up Arona and powerbombed him into the canvas earning the KO win.
Jackson resides in Ladera Ranch and has four children: D'Angelo (otherwise known as Darnell) and Raja from previous relationships, and Elijah and Naname Nakia Jackson with his wife, Yuki. All three boys have the middle name of Rampage, while Naname has Page. Yuki separated from him in 2006 after a paternity test proved that he had fathered a child, Raja, with another woman in 2000. Jackson and his wife reconciled but have since divorced. Jackson suffers from low testosterone and undergoes testosterone replacement therapy. In 2010, Jackson lived in Merseyside in the United Kingdom. He is a supporter of Everton F.C.. He is an avid gamer, and streams in his free time on the streaming site Twitch.tv.
On December 9, 2007, it was announced by Dana White at Spike TV's Video Game Awards show that Jackson will be one of the two coaches of The Ultimate Fighter 7. At the conclusion of the season, Jackson fought the other coach and number one contender Forrest Griffin at UFC 86. During the show, Jackson showed his temper after his fighters repeatedly lost to Team Forrest. Going into the semifinals, only two of Jackson's original fighters made the cut while Griffin had 6 of his fighters advance. In the finale, Team Forrest's pick, Amir Sadollah beat Team Rampage's top fighter C.B. Dollaway via armbar in the first round.
Jackson was charged with one felony count of evading police while driving recklessly, one felony count of evading police and driving against traffic, three misdemeanor counts of hit and run with property damage, and one misdemeanor count of reckless driving when he nearly hit several pedestrians. Jackson faced up to 3 years in prison if convicted. On August 28, 2008, he pleaded not guilty to all of the charges; however, on January 8, 2009, he pleaded guilty to one felony count of evading a police officer and driving against traffic, and one misdemeanor count of driving recklessly as part of a plea agreement. A judge dismissed the charges against Jackson on January 8, 2010, citing that he had successfully completed 200 hours of community Service and complied with other terms and conditions.
On September 22, 2009, Jackson wrote in a blog on his website that he was "done fighting", due to maltreatment by the UFC. On December 4, 2009, Jackson informed the community via his web blog that he would return to the UFC to finish his contract and wanted to fight Rashad Evans. At the UFC 107 press conference, Dana White stated that if Rashad Evans could defeat Thiago Silva at UFC 108, then a fight between Evans and Jackson would finally come to fruition.
In May 2010 the woman dismissed her lawsuit against Jackson. It is unclear if the two sides reached a settlement.
Jackson faced Jon Jones for the UFC Light Heavyweight Championship on September 24, 2011 at UFC 135. Jackson lost by submission in the fourth round after Jones applied a rear-naked choke. The loss marks the first time Jackson had been finished during his run in the UFC.
Jackson was expected to face Glover Teixeira on October 13, 2012 at UFC 153. However, Jackson pulled out of the bout citing an injury and was replaced by Fábio Maldonado.
Jackson made his TNA debut on the June 6, 2013 episode of Impact Wrestling, getting into a Verbal confrontation with Kurt Angle. The following week, Jackson saved Angle from an attack from the villainous Aces & Eights stable. Jackson returned on the July 11 episode of Impact Wrestling, being revealed as the fifth member of New Main Event Mafia along with Angle, Magnus, Samoa Joe, and Sting. On July 18, during the Destination X episode of Impact Wrestling, the Main Event Mafia achieved their goal of getting the TNA World Heavyweight Championship off of Bully Ray and out of Aces & Eights' hands after stopping them from interfering in Ray's match with Chris Sabin. After Angle took a leave of absence in August, Jackson attempted to recruit his Bellator 106 opponent Tito Ortiz to sub for him. Ortiz later attacked Jackson by hitting him in the head with a hammer, which helped Bully Ray regain the World Heavyweight Championship and go on to join Aces & Eights. Jackson made his in-ring debut in a five-on-five tag team match on the August 22 episode of Impact Wrestling; The Main Event Mafia (Jackson, Magnus, Joe, and Sting) and A.J. Styles defeated Aces & Eights after Styles pinned Devon for the win, forcing him out of TNA in the process. On September 12 at No Surrender, it was announced that Bellator MMA had pulled Jackson from TNA programming due to his upcoming PPV fight with Ortiz, thus removing him from the Main Event Mafia.
In 2014, Jackson claimed that the reason of his reckless driving was trying to reach a friend's house in order to stop him from committing suicide.
Jackson faced Fábio Maldonado on April 25, 2015 at UFC 186. However, on April 7, Jackson was removed from the card after his most recent employer Bellator MMA was granted an injunction by a New Jersey Superior Court judge preventing him from competing for the UFC after it was alleged that he breached a deal signed in June 2013. On April 21, a judge in the Superior Court of New Jersey's Appellate Division overturned the injunction against Jackson, allowing him to compete for the UFC. The bout took place at a catchweight of 215 lbs. Jackson won the fight by unanimous decision.
Jackson fought Satoshi Ishii on June 24, 2016 at Bellator 157. He won via split decision.
On November 9, 2017, Jackson re-signed a multi-fight contract with Bellator.
Jackson faced Chael Sonnen in the quarterfinals of the Bellator Heavyweight World Grand Prix Tournament on January 20, 2018 at Bellator 192. He lost the fight via unanimous decision.
