The Senators defeated Vancouver three games to two in the best-of-five-game series to become the first team to win back-to-back Cup championships since the 1912/1913 Quebec Bulldogs.
[1] Ottawa won the first half of the 1920–21 NHL regular season while the Toronto St. Patricks won the second half, setting up a two-game total goals series between the two clubs to determine the NHL title.
However, team manager Charlie Querrie agreed to give the players a bonus for the playoffs.
Then in the fifth game, Jack Darragh scored both of Ottawa's goals in the 2–1 victory to clinch the Cup.
In game one, played under western rules of seven-men hockey, the Millionaires took a 2–0 lead after the first period on goals by Alf Skinner and Art Duncan.
Smokey Harris scored in the second to stretch the lead to 3–0 before Darragh put Ottawa on the board with five minutes to play in the second.
[2] In game two, played under eastern rules of six-man hockey, the Millionaires took the lead 3–2 after one period on goals by Harris, Duncan and Jack Adams.
Ottawa took the lead in the second with goals by Cy Denneny and Sprague Cleghorn before Jack Adams countered for Vancouver seven minutes later.
Ottawa held off the Millionaires with a strong defensive third period to win the game and take the series lead.
Cleghorn then decked Cook with a punch to the jaw and a free-for-all broke out, only ended by the police going onto the ice.
The following Senators players and staff were members of the Stanley Cup winning team.