YouTube star Kristen Hanby threw a punch at his prankster rival Vitaly at. the open workout ahead of their boxing fight.
The social media stars have been sharing digs since announcing their bout earlier this year, but their rivalry turned physical at a media workout in London on Wednesday.
Vitaly, from Russia and representing Team USA in a battle with Hanby's Team UK took to the stage drowned by a chorus of boos, before making way for Hanby.
