Columba's pack did the groundwork and Gareth Long made the break for Simon Nicholls to go in under the posts after 12 minutes at Torpoint.
Argaum replied almost immediately with a Steve Tomlinson penalty, but as Columba piled on the pressure, a good ball won just inside their half was quickly shipped to Si Nicholls, who ran in for his second try. Flanker John Dowling converting.
Phil Morgan went in unconverted from a short penalty for Argaum, and a series of tap penalties concluded with Dowling kicking for goal to give Columba a 15-8 lead on the half hour.
Argaum responded, as Kevin Quigley picked up a loose ball with Tomlinson's kick to even the score, and just on the 40 minutes a break against the run of play gave Phil Hall the try that stole the lead for the Chiefs. Tomlinson converting.
Argaum put the early pressure on the home defence, who woke up but failed to make any impact until the last minute of the game, when a series of rucks saw centre Karl Long crash over and fly half Craig Walters' kick make it 22-all.