Hong Kong fighter Rex Tso, right, fights with Japanese fighter Hirofumi Mukai at the WBO Asia-Pacific super flyweight title boxing match in Hong Kong, Saturday, March 11, 2017. Tso knocked down Mukai in 8 rounds. (RSS/AP Photo/Vincent Yu)
Hong Kong fighter Rex Tso, right, fights with Japanese fighter Hirofumi Mukai at the WBO Asia-Pacific super flyweight title boxing match in Hong Kong, Saturday, March 11, 2017. Tso knocked down Mukai in 8 rounds. (RSS/AP Photo/Vincent Yu)