Anthony Ast, Kale Kessy, Jackson Houck and Mason Geertsen also scored for the Giants (5-11-0), who scored four unanswered goals to take the lead for good.
Kyle O'Connor, Jon Martin and Sam Reinhart each scored for the Ice (4-10-1).
Payton Lee made 21 saves in net for the Giants, while Wyatt Hoflin and Mackenzie Skapski combined to stop 22 shots.
Tvrdon gave Vancouver the lead 10:05 into the first period.
Martin tied the game for Kootenay just 1:40 into the second with a short-handed goal, but from there it was all Vancouver.
Ast, Kessy and Houck each scored in the second and Tvrdon added his second goal just over a minute into the third to give Vancouver a 5-1 lead.
O'Connor and Reinhart scored for the Ice, but Geertsen's goal in the final minute of the game put the result beyond doubt.