Pirates started the match well and piled the pressure on the Swallows goal in the opening stages.
Alton Meiring almost scored on his Swallows debut in the 22nd minute when he just failed to capitalise on a poor back-pass by Lehlohonolo Seema to keeper Francis Chansa.
The Buccaneers should have taken the lead in the 29th minute when Excellent Walaza latched onto a good cross by Lucky Lekgwathi, but the failed to hit the target.
Rudzani Ramudzuli wasted a glorious chance to put the hosts ahead three minutes later when he was played clear by Teko Modise, but again the finish was woeful.
The match remained goalless at the break.
Swallows came out with all cylinders firing in the second stanza and almost went ahead in the 65th minute when Tsweu Mokoro failed to hit the target following a superb cross by Oerson.
Meiring should have put the Birds ahead four minutes later, but Pirates’ keeper Chansa rushed off his line to make a superb save.
However, Swallows deservedly went ahead in the 71st minute when Oerson fired home from inside the area.
Although Pirates pushed more men forward in the final 10 minutes, they were unable to penetrate the Swallows.