Internationally, Canada had long been protesting the Soviet Union's use of "professional amateurs" at the World Championships and the Olympic Games, which were amateur events. Canada withdrew from international competition in 1969 and boycotted the 1972 Olympic hockey tournament. As an alternative, NHL Players' Association executive director Alan Eagleson negotiated a deal with Soviet authorities to hold an eight-game series between the Soviet national team and Canada's top professionals.
The tournament was the NHL's response to the defection of players to the WHA. Bobby Hull was barred from playing, as was any other player who signed a contract with the rival league, which was a heavily criticized move. Prime Minister Pierre Trudeau sent a telegram to NHL president Clarence Campbell, expressing his "intense interest which I share with millions of Canadians ... that Canada should be represented by its best hockey players, including Bobby Hull". Echoing the feelings of the public, Hull called the decision "crazy", and stated that "I'm a Canadian and I want to play for my country. I don't know why the NHL has to be so petty over this. I want to do this for Canada." The NHL did not relent.
The series was tied at three wins and a tie apiece entering the eighth and deciding game, with millions of Canadians watching "the game of the century". With the game tied at five late in the third, the Soviets were met with a concerted Canadian attack in the final seven minutes. With 34 seconds remaining in the game, Esposito took a shot at Vladislav Tretiak from 12 feet out. Paul Henderson scooped up the rebound and put it past the fallen Soviet goalie to score the goal that won the game, 6–5, and the series. Later, Alexander Yakolev, the former Soviet ambassador to Canada, argued that the Summit Series planted the seeds of glasnost and perestroika in the Soviet Union, as it was one of the first times that the Soviet people had seen so many foreigners who had not come to do harm, but to share in the game.