Harbour wrestled the Challenge Shield from Taieri with a 36-22 win against Taieri at Peter Johnstone Park.
Harbour leads the competition standings with 37 points and collects the Speight's Jug for that effort.
University A thrashed Kaikorai 62-17 at the University Oval.
Southern had a 28-3 win against Green Island at Bathgate Park.
The Magpies scored twice in injury time to snatch a four-try bonus point in an otherwise dreary game.
Dunedin demolished Pirates 58-13 and Alhambra-Union prevailed 41-32 against a much-improved Zingari-Richmond outfit.