Low Blow! Boxing Champ's Son Punches Opponent In The Groin.

Ron Dicker

That’s below the belt, kid

The school-age son of WBO middleweight champ Billy Joe Saunders started his dad’s weekend fight early, sucker-punching opponent Willie Monroe Jr. during the London weigh-in.

When Monroe tussled the boy’s hair as he stood on the stage, Stevie Saunders pounded him in the groin and kicked him, the video above shows. And he appeared to do it with a smile.

(Tony O'Brien / Reuters)

Saunders explained on Twitter that the lad was merely doing as he was taught ― to strike and run when touched by a stranger.

But Monroe wasn’t having it. According to the BBC, he accused promoter Frank Warren of somehow encouraging the boy to attack. “Warren should be ashamed of himself,” Monroe said.

(Tony O'Brien / Reuters)
(Tony O'Brien / Reuters)

On Saturday, Saunders required no help from his kid to defeat Monroe by decision to retain his title, The Sun reported.

(Leigh Dawney via Getty Images)

Afterward in the ring, Saunders handed the microphone to his son, who offered this warm apology to Monroe: “Sorry for punching you in the nuts!”

Saunders said in the post-fight press conference below that his son had “overstepped the mark a little bit” and that it won’t happen again.

  • This article originally appeared on HuffPost.