Ryan Keenan and Mitch De Snoo also had hat tricks for Whitby, which takes a 1-0 lead in the best of five series for Canada's box lacrosse junior championship.
Michael MacDonald scored twice for the Ontario team, while Curtis Knight, Stedan Diachenko, Jordi Jones-Smith, Austin Shanks and Chad Tutton added singles. Alexis Buque made 55 saves for the win.
The Warriors scored nine goals in the third period to pull away from the team from British Columbia.
Luke Gillespie and Connor Robinson each had a pair of goals for New Westminster, while Anthony Malcolm and Josh Byrne also found the back of the net.
Frank Scigliano stopped 33 of 43 shots in 50:29 of play for the Salmonbellies. Ross Bowman turned aside one of the nine shots he faced for New Westminster.