Former World Boxing Council junior featherweight (super bantamweight) champion Kazuo ‘’Royal’’ Kobayashi died of esophagus cancer on Nov. 17 at a hospital in his hometown of Kumamoto Prefecture, southwestern Japan, it was learned on Dec. 8. He was 71.

Kobayashi, a quarterfinalist at the 1972 Munich Olympics, turned pro in February 1973 from Kokusai Boxing Sports Gym and piled up knockout victories with his devastating punching power, winning the first 18 straight bouts, including 15 KOs.

He took a crack at the World Boxing Association featherweight title held by Alexis Arguello of Nicaragua in October 1975 but was knocked out in the fifth round with Arguello’s tremendous body shot.

Kobayashi moved down to the junior featherweight, challenged Rigoberto Riasco of Panama for the latter’s World Boxing Council junior featherweight title in October 1976 and captured the crown by knocking him out in the eighth round, becoming the first Japanese Olympic-experienced boxer to win a world title.

But his reign as the champion lasted only 46 days, the shortest in the Japanese history until now, as he dropped a decision loss to South Korea’s Yum Dong Kyun in November that year.

He returned back to the ring in the following year and challenged WBC junior featherweight champion Wilfredo Gomez of Puerto Rico in January 1978 in a highly touted match. Kobayashi fell prey to Gomez’s short but powerful left hook and was knocked out in the third round.

Kobayashi moved up the weight again and challenged Eusebio Pedroza of Panama for the latter’s WBA featherweight title in January 1979 but was knocked out in the 13th round.

In the meantime, he won the Oriental and Pacific Boxing Federation featherweight crown in April 1978 and successfully defended the title seven times. He lost the title in October 1981 and hung up his gloves. His professional record was 35 wins, including 27 KOs, against eight losses.

After retirement, he served as a trainer at a few boxing gyms before returning to his hometown of Kumamoto, where he worked for a security company.