The NHL's first superstar was "Phantom" Joe Malone. A two-time NHA scoring champion, Malone scored five goals for the Montreal Canadiens in a 7–4 victory over the Ottawa Senators on the NHL's opening night. Malone went on to record a league-leading 44 goals in 20 games in 1917–18. He again led the NHL in scoring in 1919–20, scoring 39 goals in 24 games with the Quebec Bulldogs. During that season, on January 20, 1920, Malone scored seven goals in one game against the Toronto St. Patricks, a record that still stands today. Malone was elected to the Hockey Hall of Fame in 1950.
The first goal in NHL history was scored by Dave Ritchie of the Montreal Wanderers one minute into a 10–9 win over Toronto, which was the only victory the Wanderers recorded in the NHL. On January 2, 1918, a fire destroyed the Montreal Arena, home to both the Wanderers and the Canadiens. While the Canadiens relocated to the 3,000-seat Jubilee Arena, Lichtenhein chose to withdraw the Wanderers, citing the lack of available players due to the war. The NHL continued on as a three-team league until Quebec returned to it in 1919.
In its first years, the NHL continued the NHA's split season format. The first-half champion Canadiens fell to the second-half champion Toronto team in the 1918 playoffs for the O'Brien Cup by a combined score of 10–7 in a two-game, total goals series. The victory gave Toronto the right to face the Pacific Coast Hockey Association's champion, the Vancouver Millionaires, in the Stanley Cup final. The Torontos defeated Vancouver to become the first NHL team to win the Cup.
The Canadiens won the NHL championship over the Senators in 1918–19, and traveled west to meet the PCHA's champion, the Seattle Metropolitans. The series is best remembered for its cancellation with the series tied at two wins, two losses, and a tie (2–2–1) due to the Spanish flu pandemic. Several players from both teams became ill, prompting health officials in Seattle to cancel the sixth, and deciding, game. Canadiens defenceman Joe Hall died as a result of the flu on April 5, 1919.
Meanwhile, defending champions Toronto finished in last place in both halves of the 1918–19 season. On February 20, 1919, Toronto informed the league that it was withdrawing from competition. The NHL avoided being reduced to two teams for 1919–20 when the team was reorganized as the Toronto St. Patricks. The Quebec Bulldogs also returned, increasing the league to four teams. The Bulldogs posted a 4–20 record in their one season in Quebec, despite the return of Malone, before relocating to Hamilton, Ontario to become the Hamilton Tigers in 1920.
Throughout, Livingstone continued to try to revive the NHA, convening league meetings on September 20 and December 11, 1918, which representatives of the Canadiens, Senators and Wanderers determined to close out the expired league for good.