Pirates beat Green Island 45-27 at Hancock Park because it had more control in the forwards and was able to dictate the game.
No 8 Daniel Crichton and flanker Josh Clark were key lineout forwards and were also effective in driving through the centre.
Paul Miller added his weight to the powerful forward drives in the second spell.
Pirates had a dominant scrum and veteran veteran prop Daniel Johnson used his experience to make life difficult for Green Island.
Pirates scored three first-half tries and led 28-12 at the break.
Crichton won the lineout for the first try and then used his strength to break the line after two quick phases.
The third try was scored by first five-eighth Glenn Dickson after Pirates had snaffled a Green Island lineout throw.
Pirates consolidated its position with two more tries and led 38-17 after 26 minutes in the second spell.
But it was never able to be complacent because of Green Island's ability to feed off scrap ball and counter-attack from all parts of the paddock.
It scored three tries in the second spell and closed the gap to nine points with eight minutes left.
The key players for Green Island were blindside flanker Mika Mafi, who was dangerous close to the line and scored two tries, and centre Telusa Veainu, who used his strength to break up the centre.
Halfback Dean Moeahu's long passes gave his outsides space.
The best Pirates backs were centre Ben Hanley, halfback Steve Bruce and Dickson.
- Pirates 45 (Kenton Leiataua, Ben Hanley, Isaac Beach, Glenn Dickson, Daniel Crichton 2; Dickson 3 con, 3 pen); Green Island 27 (Telusa Veainu, James Spooner, Mika Mafi 2, Hanipale Galo tries; Dean Moeahu con). Halftime: 28-12. Referee: Todd Pullar.