In June 1976, professional wrestler Kanji "Antonio" Inoki took on iconic American boxer Muhammad Ali at the Nippon Budokan arena in Tokyo in a fight that would be broadcast to an estimated global audience of 1.4 billion.

The vaguely comical bout, which ended in a face-saving draw, has been described as a precursor to modern mixed martial arts.

More than 40 years later, professional wrestling in Japan looks very different now than it did in the capital on that rainy Saturday. On Oct. 8, International Wrestling Grand Prix heavyweight champion Tyson Smith, better known by his ring name Kenny Omega, defended his title at Tokyo's Ryogoku Kokugikan in an unusual three-way match against Kota Ibushi and Cody "the American Nightmare" Rhodes at New Japan Pro-Wrestling's King of Pro-Wrestling event.