Serving London Mayor and Member of Parliament for Uxbridge and Ruislip, Boris Johnson, rugby tackled 10-year-old Toki Sekiguchi during a mini-pitch game in Tokyo.
Boris Johnson, dressed in a shirt and tie, ended up on the ground next to the youngster, who was pictured wincing in pain.
But the boy, named as Toki Sekiguchi, was soon up and running again.
He said: “I felt a little bit of pain but it’s OK,” adding it was “enjoyable” meeting the mayor.
In a series of stills, the Mayor is shown grasping the ball in his right hand and making a lunge past the youngster.
The boy tries gamely to slow him by grabbing Mr Johnson’s arm.
Undeterred, the Mayor ploughs forward, his arm now entangled with the boy’s, and both players are sent tumbling to the floor.
Mr Johnson lands on his hands and knees while the boy hits the ground on his back.
The Mayor of London has a history of overenthusiastic tackles, having tripped over a nine-year-old boy during a kickabout near Tower Bridge last year.
And during a charity football match in 2006 Mr Johnson, then MP for Henley, excruciatingly took out former German internationalMaurizio Gaudino with an headbutt to the groin.