David deKastrozza put away a Sam Carrick pass with 1:38 left in regulation Sunday afternoon, and Idaho topped the Wranglers 3-2 in Las Vegas.
Idaho improved to 20-7-4 overall. The team did not pick up its 20th win last season until Jan. 27.
Carrick and Justin Dowling also scored for the Steelheads. Dowlings goal was his 11th of the season and his 42nd point overall, the top active total in the ECHL.
Goaltender Josh Robinson picked up his 12th win of the season, stopping 34 of 36 shots.