Kyle Becker scored twice in the first period for Medicine Hat (17-6-2), which had six-straight goals to open the game.
Blake Penner, Mason Shaw and Mark Rassell also found the back of the net for the Tigers.
Matt Bellerive snapped the shutout at 18:33 of the third period for Vancouver (9-16-0), in its fourth-straight loss.
Marek Langhamer made 24 saves for the win. Payton Lee started the game in goal for the Giants, but was pulled after stopping 19-of-22 shots in 27:25. Cody Porter made 18-of-21 saves in relief.
Medicine Hat scored three times on six power-play opportunities while Vancouver went 0 for 5.
BLADES 5 WHEAT KINGS 4 (OT)
BRANDON, Man. — Brett Stovin scored his fourth goal of the season 1:35 into overtime as Saskatoon edged the Wheat Kings.
Ryan Coghlan, Nikita Soshnin, Cameron Hebig and Landon Welykholowa rounded out the attack for the Blades (7-16-1). The win snapped Saskatoon's four-game winless drought.
Tim McGauley found the back of the net at 19:50 of the third period to tie the game for Brandon (19-5-2). John Quenneville, Reid Duke and Quintin Lisoway also scored.
RAIDERS 4 OIL KINGS 3
EDMONTON — Sawyer Lange scored one of three straight goals in under five minutes in the second period as Prince Albert hung on to beat the Oil Kings.
Jayden Hart, Matteo Gennaro and Simon Stransky supplied the rest of the Raiders (12-13-0) offence. It was their fourth-straight victory.
Ashton Sautner, Brandon Baddock and Lane Bauer chipped in for Edmonton (12-10-4).
WINTERHAWKS 4 ROYALS 2
PORTLAND, Ore. — Oliver Bjorkstrand struck twice as the Winterhawks doubled-up Victoria.
Blake Heinrich and Dominic Turgeon also scored for Portland (12-12-3), which won its third straight.
Greg Chase and Brandon Fushimi replied for the Royals (14-12-2).