Centre Siaosi Folau enhanced his growing reputation with another strong performance as Harbour comprehensively beat Green Island at Watson Park.
Folau combined well in midfield with Aaron Bancroft and used his strength to crash over for two tries as he capitalised on the domination of his forward pack.
Harbour marched Green Island back in the scrums, and was far superior in tight, driving play as the forwards set the platform for the five tries and the retention of the Speight's Challenge Trophy.
Bancroft was always dangerous with his elusive running and he scored the first and last tries in a match which was called off 10 minutes early by referee Dave Kennedy with the consent of the captains.
Chilling wind and rain lashed the already waterlogged ground and the game ended in the murky gloom.
The referee called both captains out for a long lecture after an all-in brawl 13 minutes before half-time but frustration was, perhaps, understandable given the conditions.
Hooker Peter Mirrielees was a fine leader of the Harbour forwards who all played well.
Loosies Brad Griffiths and Jason Kelly were particularly prominent but they thrived on the dominance of their tight five.
Henry Holdaway was a lively halfback and the backs played sensibly with Bancroft and Folau directing operations well and not attempting to be too ambitious in the conditions.
Green Island had its moments but this was not a match it will recall with pleasure.
Blindside flanker Sam Collins and lock Jonathan Griffins were admirable workers but the pack as a unit was outplayed and the backs had few chances to make an impact on attack.
Harbour 27 (Aaron Bancroft, 2, Siaosi Folau, 2, Oka Saneviria tries, Jonnie Hughes 1 conversion); Green Island 0.
Halftime: 15-0.
Referee: Dave Kennedy.
