Next, on April 29, 1978, Urquidez faced his fourth Japanese opponent Shinobu Onuki in Tokyo; the event was co-promoted by the AJKBA and Shin-Kakutojutsu Federation. Eventually, Urquidez executed a throw that dislocated Onuki's shoulder. Initially, because of the throw, Urquidez was given a TKO loss, however, the promoters acknowledged that Urquidez used the throw without knowing it was illegal under Japanese rules; the bout was then scored as a no-contest. Following this unsatisfactory result, the two faced each other again in Las Vegas on January 2, 1980. The fight was aired by NBC, and this time Urquidez knocked out Onuki with a left hook to the body. Later, in October 1981, when the AJKBA merged with the WKA, the WKA transmuted the original Onuki no-contest to a TKO victory for Urquidez because, in fact, Urquidez's fight contract had permitted throws.