Masaharu Funaki, best known under his stage name Masakatsu Funaki is a Japanese professional wrestler who performed in New Japan Pro Wrestling, PWFG, as well as the UWF. He is also the co-founder of Pancrase along with Minoru Suzuki, one of the first modern-day non-rehearsed shoot wrestling promotions (following five years after the inception of Shooto but predating America's Ultimate Fighting Championship).

Not only the organization's co-founder, Funaki was also one of Pancrase's most successful fighters to date, scoring submission victories over the likes of Ken Shamrock, Frank Shamrock, Guy Mezger, Yuki Kondo and Bas Rutten through the course of his 50-fight career. He is the only fighter in mixed martial arts to hold wins over both Shamrock brothers and Bas Rutten, and was the first man to win the King of Pancrase title twice.

Many mixed martial arts pundits point to his second meeting with Bas Rutten as one of the most significant bouts in the sports' modern epoch, its excitement helping the sport reach the mainstream appeal it currently enjoys in Japan.

Funaki retired from competition after a win over Tony Petarra in September 1999 due to accumulated injuries and, according to fellow Pancrase fighter and friend Bas Rutten, being burnt out from the hectic Pancrase schedule. However, in 2000, he returned for a fight against Rickson Gracie. Though Funaki scored the first takedown of the bout and subsequently broke Rickson's orbital bone, he was ultimately defeated by a rear-naked choke. Funaki refused to submit to the hold, passing out before the referee intervened.

In 2006, he was elected to the Wrestling Observer Newsletter Hall of Fame. According to Sherdog.com's ratings, he was one of the top four mixed martial artists in the world from 1993 to 1998 (being the top-rated mixed martial artist in 1996) and is currently rated as the second most successful Japanese fighter of all-time behind Kazushi Sakuraba.[citation needed]

On August 2007 he and Keiji Muto discussed the possibility of Funaki returning to regular professional wrestling in Muto's company, All Japan Pro Wrestling.

On 12/31/2007, Funaki fought Kazushi Sakuraba at the K-1 Dynamite event at Kyocera Dome Osaka. Funaki almost caught Sakuraba with a kneebar early in the opening round, but eventually tapped out due to a kimura near the end of Round 1.

Funaki signed a contract with FEG's MMA promotion, DREAM. On April 28, 2008, Funaki participated in DREAM's first ever Middle-weight Grand Prix. Funaki was matched against legendary Japanese fighter Kiyoshi Tamura at the opening round of the DREAM.2 Middleweight Grandprix 2008 in Saitama, Japan. 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 0:57 of Round 1. This was his first (T)KO stoppage loss since September 14, 1998, when he was knocked out with a body blow by Semmy Schilt. Funaki was eliminated from the Middle-weight Grand Prix.

After losing twice in a row since Funaki's 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 DREAM.6 Middleweight Grandprix 2008 Final round event that took place on September 23, 2008 at the Saitama Super Arena in Saitama, Japan. Funaki fought the Japanese fighter and fan favourite "Minowaman" Ikuhisa Minowa.

At the opening seconds of the first round of the match, Funaki threw a left high roundhouse kick and followed it immediately with a right high back-roundhouse kick which both missed, and at this moment, Minowa caught Funaki's right leg and off-balanced Funaki, taking him to the ground. Minowa threw a couple of punches to Funaki that didnt do any damage, while Funaki went for a knee bar on Minowa's left leg. Minowa immediately tried to defend and counter with a leg lock, but was not successful. After a back-and-forth battle between the two to get a leg lock, Funaki attempted a successful heel hook and Minowa tapped ending the match at 00:52 seconds into the first round.