A Steve Schimmel double has seen Kamo book their place in Saturday's Stafford Choat football final against Tikipunga.
However, Schimmel and his teammates had to work for the 2-0 result after Onerahi brought their 'A' game on Tuesday night.
Kamo coach Nick Smith credited Onerahi for their play, particularly in the first spell.
"They [Onerahi] played very well, particularly in the first half," Smith commented. "In the first 20 minutes or so they came out fired up and had a whole string of corners. They really took the game to us at the start. Then, we slowly got into."
Smith said Kamo managed a much better second half after his side stuck to the game plan.