He is also the co-founder of Pancrase, one of the first mixed martial arts organizations and non-rehearsed shoot wrestling promotions (following five years after the inception of Shooto but predating America's Ultimate Fighting Championship).

He was in the same class as Keiichi Yamada (better known as Jyushin Thunder Liger), Keiji Mutoh, Shinya Hashimoto, Minoru Suzuki, Masahiro Chono, and Chris Benoit.

Along with the former Highschool Wrestler Minoru Suzuki, Funaki formed a strong bond with the dojo's head grappling instructor, Yoshiaki Fujiwara.

Funaki did, often teaming with fellow wrestler Akira Nogami have many memorable matches with Yoji Anjo and Tatsuo Nakano belonging to UWF and became the first person to take the Shooting Star Press from Yamada.

Around the same time, Funaki was scouted by K-1 executive Kazuyoshi Ishii to compete in their '93 GP tournament, but he declined, having set his sights on MMA.

In essence, in order to entertain the crowd, Funaki and Suzuki would occasionally give their opponents opportunities to create drama before finally finishing them off.

"[8] Frank Shamrock added, "I know for a fact those guys (Funaki and Suzuki) were light years ahead of everyone else, and they were so good that they would go towards entertainment before they finished a match.

Although Funaki led the pace of the match earlier with strikes, Shamrock captured his back, took him down and eventually submitted him with an arm triangle choke, winning the fight.

Funaki closed the first four Pancrase events with a win against Kazuo "Yoshiki" Takahashi, overwhelming him with palm strikes and knees to the face for the KO.

Masakatsu led him to the ground and sieged Rutten's guard, and after the Dutchman got distracted after an accidental illegal strike, Funaki caught his leg and executed a toehold, making his opponent submit.

He submitted Todd Bjornethun at the first round with a sequence of yoko-tomoe-nage into mount to armbar, and then faced Vernon White in a longer match, with Funaki making a wide usage of triangle chokes and sweeps in order to get a top wrist lock.

In 1995, after taking revenge on Jason DeLucia by defeating him via submission, Funaki was pitted against Frank Shamrock, Ken's adoptive brother and next rising star of the company.

Funaki again showed his newfound affinity for working from the bottom, fending Frank off from his guard and catching him in a triangle choke/kimura combination for a rope escape, before finishing him with a toehold.

Funaki mocked Frank, keeping his hands low and even throwing a flying spinning heel kick in an instance, but he was caught in a choke and forced to spend a rope escape before returning the favor with a triangle armbar.

Despite Funaki's body being very broken down from injuries, he returned for a fight against the legendary Rickson Gracie at Colosseum 2000 held at the Tokyo Dome.

There was no championship title at stake and Rickson got the majority of his demands, with elbows and knees to the head being rendered illegal standing or on the ground.

Masakatsu looked stunned while Rickson bloodied his face with ground and pound, and finally Gracie forced his way into a rear-naked choke.

After a hard opening exchange between the two, Funaki was staggered by a punch and pulled guard on Tamura, from where he was pounded to an eventual TKO at 57 seconds of Round 1.

After losing twice in a row since his comeback to the MMA ring, Funaki was determined to prove that he was still a worthy competitor of the sport and participated again in the promotion's middleweight division.

Minowa escaped the hold, but Funaki maintained control of his leg and immediately attacked with a heel-hook from the cross-body position, forcing his protege to tap at 52 seconds of the first round.

On August 31, 2009, Funaki signed a one-year contract with All Japan, following a tag team victory with Mutoh against Minoru Suzuki and Masahiro Chono.

[14] On July 29, he defeated the man who had injured him, Yuji Nagata, in a grudge match to become the number one contender to the Triple Crown Heavyweight Championship.

[17] In June 2013, Funaki announced his resignation from All Japan in the aftermath of Nobuo Shiraishi taking over as the new president and Keiji Mutoh leaving the promotion.

[19] After becoming a freelancer, Funaki returned to All Japan on November 11, 2015, teaming with Kendo Ka Shin to defeat Suwama and Hikaru Sato.

[27] At Wrestle-1's July 6 event, Funaki defeated Pro Wrestling Zero1 (Zero1) representative Kohei Sato to win the World Heavyweight Championship.

[36] Funaki wrestled his first match as a freelancer on August 18, 2015, at a Masahito Kakihara cancer benefit show, where he and Minoru Suzuki defeated Mitsuya Nagai and Takaku Fuke.

[37] On September 18, Funaki won his first title since becoming a freelancer, when he defeated Real Japan Pro Wrestling (RJPW) wrestler Super Tiger to win the Legend Championship.