When Frank Patrick and Lester Patrick, owners of the Pacific Coast Hockey League (PCHA) Seattle Metropolitans raided the Blueshirts roster and signed away its players, Livingstone transferred the Shamrocks roster to the Blueshirts. The league seized the Shamrocks franchise from Livingstone a week after they demanded he sell the franchise, primarily because the other NHA owners did not want one owner, particularly one they did not get along with, having two votes. Livingstone was unable to comply with the demand he sell the Shamrocks because there was now nothing left to sell, since the club had no players.
It also angered the other owners that they were now a five team league due to Livingstone being unable to retain the Blueshirts roster and operate two clubs, not only forcing one club to be idle each week, but also meaning that road trips to Toronto would be for one game instead of the more economical two, as in the past.
Toronto was led by Reg Noble, who scored 30 goals and 10 assists in 20 games for 40 points, third overall in the league behind the prolific Joe Malone of the Canadiens who scored a spectacular 44 goals in just 20 games as part of his league leading point total. Corbett Denneny and Harry Cameron also were standouts for Toronto, with 29 and 27 points respectively, good for fifth and sixth in league scoring. Toronto's Harry "Hap" Holmes came in second to Georges Vezina of Montreal in the goaltending department with a goals against average of 4.80 in 16 games.
The best-of-five series was played entirely at the Arena Gardens. Game 1 took place on March 20th and was won by Toronto 5-3 playing under NHL rules. Game 2, under PCHA rules, which allowed forward passing and retained the use of the Rover position, delivered a 6-4 victory to Vancouver.
Toronto went ahead 2 games to 1 with a 6-3 win while back under NHL rules for Game 3. The subsequent Game 4 with PCHA rules resulted in the Millionaires tying the series at two games apiece after a humiliating 8-1 demolition of their NHL adversary, forcing a deciding fifth game.
The fifth game took place under NHL rules, which gave Toronto an apparent advantage while playing at home. Denneny eventually scored the game winning goal to clinch the Stanley Cup for Toronto in a narrow 2-1 win for the Blueshirts on this date in 1918, making them the first NHL team to ever win the Stanley Cup.
As a result of this lawsuit, the Arena Gardens formed a new company, the Toronto Arena Hockey Club Company, to own and run a hockey team separate from the Arena Gardens business in order to protect the Arena business from Livingstone's lawsuits. The NHL then awarded a "new" franchise to the Hockey Club Company. This club was officially named the Toronto Arenas and, not surprisingly, was stocked with the same players from the 1918 championship club. When his players were yet again not returned to him for the 1918-19 season, Livingstone sued the Arena Gardens.