On January 22, 1976, in a game against the Detroit Red Wings at Nassau Coliseum, Potvin scored three goals (two on the power play) and also added an assist while his brother Denis had two goals and two assists of his own. Jean's final two goals came 45 seconds apart as he became the only defencemen in Islander history to ever score three goals in a period at the Coliseum. It was also the first time since 1947 that brothers had combined for at least five goals in an NHL game, and the first time in NHL history that it had been done by two defencemen. Potvin's hat trick is the only one by an Islanders defenceman not scored by Denis.