England Under-20 flanker Seb Kelly was sent off for a headbutt as his team’s hopes of regaining the age-grade world title ended in semi-final defeat in Tbilisi, Georgia.

England had made a strong start against defending champions South Africa, with prop Ollie Streeter and fly-half Hugh Shields’ tries contributing to a 17-7 lead, when Kelly lunged at Luan Giliomee on the floor after the whistle, butting the ‘Baby Boks” full-back in the face.

Referee Kevin Bralley reviewed the incident on the advice of his television match official and issued a straight red card, reducing England to 14 players for the rest of the game.

“That is inexcusable from Seb Kelly, you can’t do that,” said former England player Tom May, who was commentating on the match for Premier Sports.

“Yes, be tough, be physical, but that is violent.”

England reached half-time with a 20-12 lead, but were overwhelmed in the second half, with South Africa scoring five tries in 20 minutes after the interval to run out 53-37 victors.

Kelly’s headbutt will be assessed by a foul play review committee on Tuesday.

The committee will propose a punishment, which Kelly can either accept, or put his case forward in a more in-depth hearing.

Italy second row Niccolo Cannone was banned for four matches for making head-to-head contact with New Zealand’s Cam Roigard in a similar incident in the All Blacks’ 47-17 win on Saturday.

However, Kelly’s headbutt appeared to involve greater force and intent. South Africa second row Bakkies Botha was banned for nine weeks back in 2010, when he drove his head into that of New Zealand’s Jimmy Cowan while the pair were on the floor.

England will take on New Zealand in Saturday’s third-place play-off, with South Africa facing France to decide the annual tournament’s champions.

England last lifted the title in 2024, when a team including Henry Pollock, Asher Opoku-Fordjour and Afolabi Fasogbon – all now part of the senior set-up – beat France in the final.