Siaosi Folau lit up a game of average quality as Harbour repulsed a strong challenge from Taieri at Watson Park.
Harbour eventually won three tries to one but the score could have been closer had Taieri been more clinical in its handling and tactical kicking.
Folau, who has played at centre for Harbour, was moved to the right wing and injected himself into the game with a high workrate which included several line-breaks and a decent kicking game.
Harbour was missing several leading players, including Peter Mirrielees and Eben Joubert, but played much better in the second spell after a muddling first half.
Taieri led 7-5 at half-time after a runaway try by centre Jared Campbell but Harbour was more assertive playing into the breeze in the second spell.
Ryan Olsen was a lively hooker, prop Ben Nolan became increasingly prominent in general play and Brad Griffiths and Jason Kelly were hard-working loose forwards.
Brenton Kramer had a modest game with the boot (two goals out of six) but Doug Edwards was a strong-running centre who linked well with Folau.
Taieri was competitive throughout.
Charlie O'Connell was outstanding from the openside flank, No 8 Eric Vaafusuaga was full of endeavour and Callum Bisset gained some quality line-out ball.
The backs made mistakes at critical times but Cody Gutsell was a determined runner on the left wing and Ryan Shortland was strong at second five-eighth.
Harbour 20 (Mehaka Wickliffe, Trent Sutton, Ra Kahukiwa tries; Brenton Kramer conversion, penalty goal), Taieri 10 (Jared Campbell try; Ricky Stewart conversion, penalty goal).
Half-time: Taieri 7-5.
Referee: Tim Baker.
