Harbour tightened its game in the second spell to beat Zingari-Richmond at Watson Park to regain the Scoles Memorial Trophy.
Harbour had played too loosely when it had the wind at its back in the in the first spell and only snatched a 7-0 half-time lead when second five-eighth Siaosi Folau scored the first of his two tries.
It was Zingari that made the early running after the break when wing Jeremy Burton chip kicked and won the race for the ball to score the try.
It was followed by a penalty goal by Jonny Noakes that gave Zingari an 8-7 lead after just five minutes.
But the rest of the game was controlled by the Harbour pack that was ably led by prop Ben Nolan who kept the scrum tight and made ground with the pick and go.
Loose forwards Jason Kelly and Eben Joubert made it difficult for Zingari to break out, while Folau was the best attacking back on the paddock and was able to punch holes in the Zingari defensive screen.
Midfield back Ben Kent had a sound defensive game for Zingari and Jonny Noakes was tidy at first five-eighth.
Flanker Ryan Newman and lock Andrew Duff were the best of the forwards.
Harbour 17 (Siaosi Folau 2 tries; Jonnie Hughes conversion, Dan Snee conversion, penalty goal), Zingari-Richmond 8 (Jeremy Burton try; Jonny Noakes penalty goal).
Half-time: Harbour 7-0.
Referee: Todd Pullar.
