Grand Forks goaltender Mason Gatz earned a 28-save shutout as the Border Bruins beat the Leafs 3-0 in Nelson on Sunday.
New goaltender Frederick Larochelle allowed two goals on 15 shots for the Leafs (3-1-0), who suffered their first loss of the season.
Cody Laybolt scored twice and Matteus Reis added one more for Grand Forks, which improved to 3-1-1.
Nelson next visits Revelstoke on Friday in a rematch of last season’s KIJHL finals, before visiting Sicamous on Saturday followed by a game in Castlegar on Oct. 11.
The Leafs’ next home game is Oct. 15 against the Beaver Valley Nitehawks.