Sundowns lost captain Themba Zwane in the 13th minute due to a thigh muscle injury, but the Brazilians continued to probe their hosts as the dominant side early into the battle.
They were duly rewarded when Teboho Mokoena headed in a corner kick delivery from Marcelo Allende nine minutes before the halftime break.
On an afternoon, Evidence Makgopa made his season debut for Pirates, alongside Deano van Rooyen and Thalente Mbatha. The former Baroka FC star was denied by the upright post with 10 minutes to go as Pirates pushed for a comeback.
However, the Buccaneers managed to hit back with three minutes remaining when Kamogelo Sebelebele beat Ronwen Williams after coming to the end of a long ball from Mbekezeli Mbokazi for his first goal in Pirates colours.
After conceding at home in this 1-1 draw, Pirates have an uphill task to overturn this result in the second leg in Tshwane against Masandawana, who now enjoy the advantage of an away goal.