The 17-year-old had just been broken to trail Edmund 6-3 6-4 2-1 in the decisive rubber of the Davis Cup tie between the two countries when he angrily hit a ball away which struck umpire Arnaud Gabas in the eye.
Shapovalov was subsequently disqualified by tie referee Brian Earley, handing Great Britain passage into the quarter-finals, and the Wimbledon junior champion has vowed to ensure that it will never happen again.
"Luckily he was OK but obviously it's unacceptable behaviour from me," he told reporters.
"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."
Earley has the authority to impose a £9,600 fine on the teenager, while the International Tennis Federation could significantly increase that punishment and suspend Shapovalov from future ties.