England Under-20 flanker Seb Kelly received a red card for a headbutt, dashing his team's hopes of reclaiming the age-grade world title in a semi-final defeat against South Africa in Tbilisi, Georgia.

The match started positively for England, as prop Ollie Streeter and fly-half Hugh Shields helped establish a 17-7 lead. However, Kelly's moment of indiscretion occurred when he lunged at Luan Giliomee, the 'Baby Boks' full-back, after the whistle, striking him in the face.

Referee Kevin Bralley reviewed the incident with the television match official and issued a straight red card, leaving England to play with just 14 players for the remainder of the game.

Commentating on the match, former England player Tom May condemned Kelly's actions, stating, "That is inexcusable from Seb Kelly, you can't do that. Yes, be tough, be physical, but that is violent."

At half-time, England led 20-12, but the second half proved disastrous, as South Africa scored five tries in just 20 minutes, ultimately winning 53-37.

Kelly's headbutt will be reviewed by a foul play committee on Tuesday, which will determine the appropriate punishment. Comparatively, Niccolo Cannone of Italy received a four-match ban for a similar offense, while Bakkies Botha was banned for nine weeks in 2010 for a more severe incident.

Looking ahead, England will face New Zealand in the third-place play-off on Saturday, while South Africa will challenge France for the championship.