In 1977, Urquidez traveled to Japan and fought under the WKA's compromise US–Japan rules which included leg kicks and knees to the body. He defeated Katsuyuki Suzuki by KO in the 6th round (August 1977) as part of the professional wrestling event in which Antonio Inoki fought Everett Eddy in what was said to be a wrestler/karate fighter mixed match but was a pre-determined pro wrestling match. The Suzuki fight materialized because the newly formed WKA organization could not compete against the PKA in the US. At the same time, Japanese professional wrestler Antonio Inoki, who gained the worldwide fame by fighting Muhammad Ali in the controversial 1976 boxer/wrestler mixed-match in Japan, had been looking for new opponents for what he called the world martial arts championship series. Eventually, promoter Ron Holmes discovered Everett Eddy for Inoki. By that time, Eddy had been coached by Arnold Urquidez, and lost in a knockout in the 1st round to PKA world heavyweight champion Ross Scott in the previous year. In the same event, Benny Urquidez knocked out Howard Jackson, but soon his lightweight title was stripped by the PKA, and so both Eddy and Urquidez had no action in the US, and had to look for fights overseas. Even though the Inoki/Eddy bout was successful, it was the fight between Urquidez and Suzuki, which shocked Japan, where Japanese kickboxing had been very popular. Though never tested for or achieved any rank in Japanese karate, Urquidez has decided to bestow upon himself the rank of sensei, a Japanese honorific term which at the most shallowest term, would mean "guide".
The All-Japan Kickboxing Association, for which Suzuki had been rated as No. 2, became interested in the American sport of full-contact karate, decided to promote series of mixed-rules bouts between the American full-contact karate fighters and Japanese kickboxers. On November 14, 1977, the AJKF held the first of such event which featured Benny Urquidez, his brother-in-law Blinky Rodriguez, Marc Costello, Brendan Leddy, Tony Lopez, Leonard Galiza and Freddy Avila. Only Benny Urquidez and Costello came out as the winners for the American team. Urquidez's victory over Kunimitsu Okao convinced the Japanese fight fans, and eventually began to be featured as the central figure for what was supposed to be the documentary comic book, The Square Ring, until he declined to avenge his loss against the Thai opponent Prayout Sittiboonlert. Urquidez's second loss came in August 1980 in Florida. American Billye Jackson dominated seven rounds including knocking Urquidez down. Urquidez protested the decision and petitioned the WKA's Howard Hansen to classify it as a non-contest.
Another three bouts were eventually ruled no-contests (NC). The first, in Los Angeles on March 12, 1977, was a nine-round NC (WKA) against Thai boxer Narongnoi Kiatbandit as part of the inaugural WKA world title event. Urquidez scored flash-knockdowns against Narongnoi in rounds three and six as well as five legal throws over three other rounds. Narongnoi was warned for illegal knee kicks and groin attacks on four occasions before being assessed with a point deduction in round nine. However, the point deduction came shortly after Narongnoi had scored his sole flash-knockdown which, in turn, provoked a riot among Muay Thai fans in the audience. The audience invaded the ring moments before the final bell. Scores were never collected for round nine. The California State Athletic Commission declared the no-contest.