Joel McCready had a hat trick for Vancouver (2-3) with Rhys Duch, Justin Salt and Corey Small adding two goals each. Tyler Digby, Tyler Hass and Brandon Clelland rounded out the attack. The Stealth outscored Colorado 11-4 in the second and third quarters.
Drew Westervelt and Joey Cupido netted hat tricks of their own for the Mammoth (3-1) in their first loss of the season. Eli McLaughlin and Jackson Decker scored two each with Adam Jones, Sean Pollock and Bob Snider adding the others.
Tyler Richards turned away 45 shots for the victory while Dillon Ward made 30 saves in net for Colorado.
Both teams went 4 for 5 with the man advantage.