The year 1910 saw the foundation of the National Hockey Association (NHA), precursor to the NHL, and Lalonde joined the Montreal Canadiens for their first season.

[7] He rejoined the Canadiens for the 1911 season—professional hockey was only then developing any sense of teams retaining the rights to their players—during which he had several stick battles and provoked the ire of opposing fans.

With the formation of the Pacific Coast Hockey Association (PCHA) in 1912, Lalonde jumped to the Vancouver Millionaires, and promptly led the league in scoring its inaugural year.

However, on the day of the sixth game of the finals against the Seattle Metropolitans, Lalonde, owner George Kennedy, Joe Hall, Billy Coutu, Jack McDonald and Louis Berlinguette were hospitalized with influenza, in the wave of the 1918 flu pandemic.

[9] Thereafter Lalonde had two fine years, but after the Kennedy estate sold the Canadiens to Leo Dandurand, his clashes with the new ownership affected his play to the point where he left the team for four games, and he was relegated to reserve duty amidst the boos of the fans.

[citation needed] On a line with future Hall of Famer Bill Cook, Lalonde achieved his final scoring title as playing coach of the Sheiks, although the team had a poor overall record.

[citation needed] Although Lalonde is best-remembered today as a hockey player, he was just as prominent in lacrosse, which in the early years of the 20th century was one of the most popular professional sports in Canada.

In 1912, he was signed to be player-manager of the Toronto Lacrosse Club, but almost immediately changed his mind and joined the exodus of players heading west for big contracts.

After coming west in 1909 as a hired-hand with the Regina Capitals to compete against the New Westminster Salmonbellies in their challenge for the Minto Cup, playing as a defenceman, Lalonde then decided to remain in British Columbia when Vancouver Lacrosse Club president Con Jones offered him a fortune of a contract rumoured in the range of $3,500 (or $72,000 in modern currency); this was more than double what he was earning with the Montréal Nationals the previous season.

To compete against that perennial powerhouse squad of legends and hated rivals, New Westminster Salmonbellies, Con Jones went out and bought the best player in Canada that money could buy: Newsy Lalonde.

He played what was back then called the inside home position – basically an attacking forward who played on the crease as the primary threat against the opposing goaltender – and his goal-scoring prowess was critically important to the success of his Vancouver team as Lalonde constantly went up against some of the finest New Westminster goaltenders of the day, stalwarts such as Alex "Sandy" Gray and then later the legendary Alban "Bun" Clark.

In an era when lacrosse was notably rough and tumble and players wore no padding, all the while swinging wooden sticks, Lalonde was one never to back down from the toughness aspect of the game.

As a fitting, final tribute to his career, Lalonde was an obvious choice for the initial inductees to the Canadian Lacrosse Hall of Fame in 1965 in the "field player" category.

Much of Lalonde's production came from his highly accurate snap shot, and his remarkable longevity which allowed him to play a physically aggressive style for upwards of 23 seasons.

Lester Patrick, co-founder of the PCHA and then-captain of the Victoria Aristocrats, claimed in 1912 that Lalonde possessed the best shot in hockey: “He shoots every bit as hard as Pitre, and is much more deadly.

"[18] Up until 1918, Lalonde cleverly used a specific rule of hockey – which stipulated that goaltenders could not drop to their knees to block shots – to complement his superb accuracy.

Coming off the right wing or down the centre, he would unleash a “wicked knee-high shot” which would catch the opposing goalie between the glove – or stick – and pad.

Lalonde's snapper was so lethal that opposing coaches would often assign three to four of their own players just to shadow him, and – in one of the earliest iterations of the trap – attempt to pin him into a corner in order to prevent his being able to get into a scoring position.