There was Helio Gracie, running around challenging anyone who would fight him. He won many of those bouts, his most famous fights were against two famous Japanese Judo champions. Helio won the first round:
In July 1951 Kimura and two other fellow Japanese Judoka were asked to compete in Brazil. Kimura at age 34 was accompanied by a 240 pound (110kg) college champion Yamaguchi (6th degree black belt at the time) and Kado (5th degree black belt). It was to be a Judo/Jiu-jitsu fight. Kado accepted a challenge from Helio Gracie – Brazilian champion for 20 years. The loser was determined by tapping out due to a choke or armbar, or by being knocked out of commission. Ippon (clean powerful throws) or osaekomi (pinning) would have no effect on the results of competition. During Kado’s fight he threw Gracie several times. Gracie, who was in excellent condition, demonstrated ukemi, braking the throws with little injury. After 10 minutes of frustration, Kado decided to apply a choke. However, the masterful Gracie applied his own choke rendering Kado unconscious. With Kado’s passing-out, Gracie was declared the winner and became a national hero of Brazil!
But the second didn’t go so well, from Wikipedia:
Hélio also fought in Brazilian Jiu-Jitsu vs. Judo matches. In 1932 he fought Japanese judoka Namiki. The fight ended in a draw, but according to the Gracies the bell rang just seconds before Namiki would have tapped out. Hélio had two fights with Japanese judoka Yasuichi Ono after Ono choked out Hélio’s brother Jorge Gracie in a match. Both fights ended in a draw. Hélio fought another Japanese judoka Kato twice. The first time was at Maracanã stadium and they went to a draw. Afterwards, Hélio asked for a rematch. The rematch was held at Ibirapuera Stadium in São Paulo and Hélio won by choke. In 1955, Hélio went on to fight leading judoka Masahiko Kimura at Maracanã stadium. While the match resulted in a clear victory for Kimura via bent armlock, Kimura outweighed Hélio by 25 kilograms (55 pounds). In 1994, Hélio admitted in an interview that he had in fact been choked unconscious earlier in the match, but had revived and continued fighting.
This is the match where Kimura employed the hold that still bears his name: