5 – Judo in MMA
As referenced in Wikipedia – Excerpt
In mixed martial arts
Several Judo practitioners have made an impact in mixed martial arts. Anderson Silva is the UFC Middleweight champion and holds a black belt in judo. Other notable Judo trained MMA fighters include former Russian national Judo championship Bronze medalist Fedor Emelianenko, UFC fighter Karo Parisyan, Olympic medalists Hidehiko Yoshida (Gold, 1992), and Ronda Rousey (Bronze, 2008).
Judo has been one of the primary martial arts displayed in Mixed Martial Arts (MMA) competitions since MMA’s inception.
The first official MMA fight, the Ultimate Fighting Competition (UFC), was held in 1993. It was advertised as a “no holds barred” fight. At the time, the public perception was that a larger/stronger human could dominate a smaller/weaker human. The fighters came from various martial arts or sports fighting backgrounds, including judo, karate, Jujitsu, boxing, wrestling, tae kwon do and kickboxing. They fought until the opponent was knocked out, tapped out (stopping the fight by tapping their hand), or the referee stopped the fight. The winner of the first Ultimate Fighting Championship was a small Brazilian, Royce Gracie, who used Judo/Jujitsu submissions to defeat opponents twice his size 
Royce Gracie is famous for his Brazilian Jujitsu, a hybrid fighting style that employs many Judo techniques.
Many MMA fights are ended by submission holds most of which derive from Judo. “Chokeholds are common in Jujitsu, judo and submission grappling, and most trainers discuss how fighter need to experience these techniques in order to learn how to resist them” 
“Judo resembles MMA’s grappling aspects, particularly when both fighters are on the ground. MMA fans would easily recognize judo’s submissions — a fighter might “tap out,” or concede the fight, when caught in a chokehold or an armbar” 
Jujitsu, Brazilian Jujitsu, and Judo all derive from one another. “For some time in Japan, Judo and Jiu-Jitsu were almost synonymous. Judo was known as Kano’s Jiu-Jitsu. Regardless, this answers the question, “why do they call it Brazilian Jiu-Jitsu and not Brazilian Judo?” Because they were essentially the same thing at the time, remember, the Gracie family was learning Jiu-Jitsu and Judo while Kano was still struggling to show the difference between the two and popularize his art. In the early 1900s there was very little difference between the two. In fact, Judo was merely a collection of Jiu-jitsu styles, whose strongest points were put together to make what then became Judo” 
The Japanese found judo superior to jujitsu because it involves both stand up and grappling techniques. “After a match-up between older styles of Jiu-jitsu and Judo at the Tokyo police headquarters, Judo was named the national martial art in Japan. It was the official art used by law enforcement in the late 1800’s, and continues to be popular to this day. During World War II, many U.S. soldiers were exposed to the art of Judo and brought it back to America with them. The first issue of Black Belt magazine here in America (1961), featured a sketch of a Judo throw and was a special Judo issue” 
Ronda Rousey, a female MMA champion, won a bronze medal in Judo at the 2008 Olympics. “Rousey eventually got an offer to try MMA and had her first professional fight last year. She has since defeated all her opponents with a judo arm lock in less than one minute and is now a champion in the combat sport” 
Anderson “The Spider” Silva has a black belt in judo and is the current UFC Middleweight Champion; he is undefeated in the UFC