Canada’s Denis Shapovalov was left mortified after joining tennis’s hall of infamy on Sunday, offering an apology and promising that he would learn from his momentary explosion of temper that left a Davis Cup umpire needing a visit to hospital.

Shapovalov, one of the brightest young talents in the game at 17, said he was “ashamed” after he inadvertently struck chair umpire Arnaud Gabas in the left eye with a ball he smashed away in anger during the Canada-Great Britain tie in Ottawa.

The incident happened in the third set of the deciding rubber with the tie locked at 2-2 and Shapovalov, the Wimbledon boys champion, two sets and a break of serve down to Britain’s Kyle Edmund.

The teenager was immediately defaulted for “unsportsmanlike conduct”, with Britain handed a 3-2 victory in the tie.

On Monday, the International Tennis Federation said in a statement: “Referee Brian Earley, who witnessed the incident, declared an immediate default of Mr Shapovalov for unsportsmanlike conduct. It was clear that Mr Shapovalov did not intend to hit Mr Gabas.

Shapovalov sought out the umpire in the referee’s office and apologised. Gabas, who suffered bruising and swelling to the left eye was sent to hospital for a precautionary evaluation.

Shapovalov issued an instant apology after the match, saying: “I feel incredibly ashamed and embarrassed and I just feel awful for letting my team down, for letting my country down, for acting in a way that I would never want to act.

“I can promise that’s the last time I will do anything like that. I’m going to learn from this and try to move past it.”

British captain Leon Smith said he could not help but feel sorry for the youngster. “I feel for the young lad. He’s a great talent and he has learned a harsh lesson,” said Smith.

People still remember how the British player Tim Henman was defaulted in a Wimbledon doubles match in 1995 when he struck a ball which accidentally struck a ball girl.

More recently, in the 2012 Queen’s final in London, Argentine David Nalbandian kicked out at an advertising hoarding at courtside in frustration, which bloodied a line judge’s shin.