HERO'S Akiyama's
mixed martial arts debut was in the
K-1 Premium 2004 Dynamite event on December 31, 2004, where he defeated
boxer Francois Botha by
armbar submission in the first round. His first defeat was to
Jerome LeBanner, who knocked him out with knees in his second fight at the HERO'S 1 event on March 26, 2005, although LeBanner is a heavyweight that came into the fight at 262 pounds (119 kg), while Akiyama came into the fight at 189.5 pounds (86 kg). He has notable wins against
Tokimitsu Ishizawa,
Taiei Kin,
Kestutis Smirnovas and
Melvin Manhoef. Akiyama defeated
Melvin Manhoef at the
Hero's light-heavyweight Grand Prix 2006 final round, and gained the champion belt. In K-1 Premium 2006 Dynamite, Akiyama fought the legendary
Kazushi Sakuraba in the main event. During the match, Sakuraba called to the referee saying "[Akiyama is] Slippery!" Akiyama went on to win the match with a referee stoppage. This created a controversy amongst MMA fans in Japan, assuming Akiyama was using some sort of body oil or lubricant, banned in K-1 rules. But at this moment, Akiyama answered to questions about the oil in the interview as follows: "I have no idea why Sakuraba felt slippery. It may be my sweat, as I sweat a lot always and it often drips off my body." On January 11, Akiyama and
FEG (the parent company of K-1) held a press conference during which Akiyama said he used
Olay lotion prior to the fight claiming that the lotion was used to treat a worn gi. Pre-fight footage also showed Akiyama casually applying six bottles of lotion to his body in his locker room. As a result, Akiyama was disqualified and his prize money was suspended. Akiyama himself was suspended indefinitely from HERO'S competition six days later. Public outcry against Akiyama did not cease however, and
Nike was swamped with complaints when Akiyama was featured on a television commercial in Japan. Though Akiyama has admitted to applying cream to his skin, he has said that the purpose was not to gain an unfair advantage but to treat his dry skin. The fight was ruled a "No Contest". Akiyama was cleared from his FEG-induced suspension and FEG announced that Akiyama would return to K-1 Hero's in
Seoul, on October 28, 2007. His opponent was
Denis Kang, who was the finalist of
PRIDE Bushido Grand Prix 2006 and making his debut in
Hero's. Though he was an underdog, Akiyama beat Kang by KO in the first round.
Yarennoka! fight On December 31, 2007, Akiyama faced Kazuo Misaki at
Yarennoka!. The rules of the match stated that kicks to the head of a downed opponent would not be allowed. Late in the first round Misaki knocked down Akiyama with left hook, and as Akiyama struggled to his feet, Misaki delivered a lunging kick to the face which knocked Akiyama out.
Ultimate Fighting Championship On February 24, 2009, it was announced on the official UFC website that Akiyama had signed a deal with the company. Akiyama made his debut against
Alan Belcher at
UFC 100 on July 11. Despite suffering a broken orbital, he won by split decision (30–27, 28–29, 29–28). It was the 1st fight in Akiyama's career that went to the judges' score cards. The bout was also awarded "Fight of the Night" honors, granting both fighters a record-setting $100,000 bonus each. On May 30, 2009, Akiyama opened a new gym in
Tokyo, Japan. The 'Akiyama Dojo' has Judo and MMA halls, 30
tatami mats and three octagonal cages. Akiyama joined
Xtreme Couture for the month of October 2009 to work on his striking skills. Akiyama was expected to face MMA legend and former
PRIDE Middleweight Champion Wanderlei Silva on February 21, 2010, at
UFC 110, but Silva instead faced British striker
Michael Bisping on the card, winning via unanimous decision. At the Post-fight conference, UFC President
Dana White stated that Akiyama had requested to fight Silva for a while and has refused to fight other opponents, after which both fighters verbally agreed to fight. Akiyama was expected to face Silva on July 3, 2010, at
UFC 116. Wanderlei had to pull out on June 22, 2010, due to fractured ribs suffered in training.
Chris Leben was chosen as a replacement. Despite controlling the majority of the fight with effective strikes and solid Judo takedowns, Akiyama became fatigued after the first round and lost via triangle choke with just twenty seconds left in the third round. His loss to Leben was his first official loss in five years. Akiyama lost to
Michael Bisping on October 16, 2010, at
UFC 120 by unanimous decision. In preparation for his fight with Bisping, Akiyama switched to
Jackson's Submission Fighting in
Albuquerque, New Mexico. It is unclear whether the switch is permanent. Even though Akiyama lost to Bisping, he rocked him in the first round. He earned his third "Fight of the Night" honors. He has now earned "Fight of the Night" honors for all three of his UFC appearances. Akiyama was briefly scheduled to face
Chael Sonnen on March 19, 2011, at
UFC 128, but, due to Sonnen's suspension, the fight was scrapped. Akiyama was later scheduled to face
Nate Marquardt at the same event, but pulled out due to the
2011 Tōhoku earthquake and tsunami and was replaced by
Dan Miller. Akiyama was defeated by
Vitor Belfort at
UFC 133 via KO (Punches) in the first round. This defeat marked the third straight loss for Akiyama in the UFC. Following the fight, Dana White stated that Akiyama most likely would not be cut from the organization if he agrees to move down to
welterweight. As of September 3, 2011, Akiyama has stated he will move down a weight class, allowing him to stay in the UFC. On November 3, 2011, a picture of Akiyama had circled the web of his body frame as a welterweight. Akiyama faced
Jake Shields on February 26, 2012, at
UFC 144. He lost the fight via unanimous decision (30–27, 30–27, 30–27). During the bout, Akiyama was able to utilize multiple judo techniques which was praised as the main highlights of the fight; despite losing the decision. Akiyama was expected to face
Thiago Alves on July 21, 2012, at
UFC 149. However, Akiyama was forced out of the bout with an injury. Akiyama had made an appearance alongside UFC featherweight
Hatsu Hioki during the Q&A session for
UFC on Fuel TV 8. During the Q&A, Akiyama stated he was thinking about returning for another bout as long as he has a free schedule as well as being matched against a well-known opponent that would interest fans. Akiyama also stated he still has interest in fighting
Wanderlei Silva, a bout scheduled for
UFC 116 but was changed when Silva had to pull out of the fight due to injury. After over two and a half years away from the sport, Akiyama returned from his self-imposed hiatus on September 20, 2014, at
UFC Fight Night 52. He was originally scheduled to face
Kyle Noke on the card. However, Noke was forced out of the bout with a knee injury and replaced by
Amir Sadollah. Akiyama won the fight via unanimous decision. After another year away from the sport, Akiyama returned to face
Alberto Mina on November 28, 2015, at
UFC Fight Night 79. He lost the back-and-forth fight via split decision.
ONE Championship After three years from his previous bout, Akiyama announced his contract with ONE Championship. Akiyama faced Agilan Thani in a co-headliner bout at
ONE Championship: Legendary Quest on June 20, 2019. He lost the bout via unanimous decision. Akiyama faced Sherif Mohamed at
ONE Championship 109: King of the Jungle on February 28, 2020. Akiyama won the fight via knockout in the first round, his first stoppage via strikes in nearly 13 years. Akiyama was initially scheduled to face Mohammad Karaki at
ONE on TNT 3 on April 21, 2021. However, the bout was cancelled and Akiyama was supposed to face
Eduard Folayang at
ONE on TNT 4 on April 28, 2021. But due to suffering an injury during training camp, Akiyama pulled out of the fight and the bout was subsequently scrapped. A 46-year-old Akiyama faced
Shinya Aoki at
ONE: X on March 26, 2022. After getting dominated for most of the first round, nearly getting submitted, Akiyama went on to win by technical knockout in the second round. Akiyama announced that he plans to fight till he is 50. Akiyama faced
Nieky Holzken in a special-rules match at
ONE 165 on January 28, 2024. The first round was under boxing rules, the second was contested a Muay Thai, and the third round was contested a MMA rules. He lost the fight via technical knockout in the first round. ==Fighting style==