Terrence Dzvukamanja started up top from the win over Cape Town City in midweek, with Linda Mntambo handed a rare start in place of Thembinkosi Lorch.
Galaxy goalkeeper Ezekiel Morake was put to countless work early on, with a double save from solid attempts from close-range by captain Happy Jele and Dzvukamanja.
The work didn't stop there for the shot-stopper, as he pulled off yet another succession of saves from a smartly taken effort by Vincent Pule.
Fortune Makaringe sliced through the defence to go clear for the breakthrough towards the final phases of the first half, but Morake once again came to his side's aid.
Morake was finally beaten just after the half-hour mark when a corner-kick from Deon Hotto allocated Thulani Hlatshwayo to head home emphatically.
The one-way traffic from the Buccaneers continued in the second half, as an attempted volley from Mntambo landed in the path of Makaringe who forced Morake to work with a low shot.
Galaxy decided to call on former Pirates development player Ricardo Lourenco midway through the second half, while Kabelo Dlamini and Jean-Marc Mundele entered for the Buccaneers.
Pirates had a second goal late on when Mntambo picked up a pass from Paseka Mako to drill a low shot past Morake and into the back of the net.
It got worse for Galaxy moments later after Mundele twisted around the area to volley home his first goal for the Sea Robbers, who comfortably contained the final minutes to claim the victory.
Pirates: Ofori, Hlatshwayo, Jele, Ndlovu, Mako, Mntambo, Motshwari, Makaringe, Pule, Hotto, Dzvukamanja.
Subs: Sandilands, Mundele, Sesane, Maela, Sam, Dlamini, Lorch