Sundowns defender Grant Kekana struck into the roof off a Marcelo Allende freekick to give Sundowns the lead 13 minutes into the contest.
Then in the 27th minute, Lucas Ribeiro Costa shot into the far bottom corner a feed from Teboho Mokoena after a solo run from Masandawana's half.
Deon Hotto gave Pirates hopes of a comeback when he reduced arrears in the 57th minute off a deflection via Lucas Suarez.
But Ribeiro was back to strike again two minutes later with another bottom corner strike and gave the Buccaneers further advantage for his ninth league goal of the season.
Teboho Mokoena then dashed Pitates' hopes of collecting at least a point when he unleashed his trademark long shot from outside the box with 12 minutes to go to cement a 4-1 victory for Sundowns and give them a nine-point lead on the PSL table.