Capitals, who lost 7-2 at Braehead on Saturday, are now level on eight points with the Renfrew club but stay in eighth spot in the ten-strong Elite League on goal difference.
Capitals caught the West of Scotland club cold and surged to a 2-0 lead inside the first ten minutes. Player/coach Richard Hartmann netted in the sixth minute followed by McKenzie.
Ryan Campbell made it 2-1 but Rene Jarolin made it 3-1 in the 28th minute and McKenzie added a fourth. Marcis Zembergs made it 5-1 eight minutes into the final session.