Tait Seguin scored twice as Caledonia topped London 8-1 to take a decisive 3-0 series lead in the Sutherland Cup Finals.
Blake Luscombe and Jordan Brown each picked up three points with a goal and two assists. Todd Ratchford had three assists for the Corvairs.
Caledonia jumped out to an early three goal lead after the first and scored another three goals in the second before Matt Bean put the Nationals on the board. Caledonia scored again in the final two minutes of the second and once more in the third.
Connor Hughes was pulled from the Nationals net after allowing six goals on 20 shots. Zack Weir stopped two shots in relief.
Mark Sinclair picked up the win for Caledonia with 27 saves.
Game 4 is tonight in London.