Celtics goals were scored by Vuyani Ntanga, Thabo Nthethe and Musa Nyatama while Lennox Bacela and Andile Jali scored for Pirates.
Celtic took the game to Pirates but missed a lot of good scoring opportunities.
The visitors scored through a volley from Vuyani Ntanga in the 39th minute to make the score 1-0.
Bucs started the second half well and had a few chances in the opening minutes.
The equalizer came in the 55th minute from a shot by Lennox Bacela.
Siwelele took the lead again in the 66th minute through Thabo Nthethe who swept Letlabika’s cross home past Meyiwa.
Mhango should have scored for Celtic in the 84th minute but hammered his shot over the bar.
Celtic were awarded a penalty in the 88th minute when Gumede brought down Lerato Lamola in the area. Musa Nyatama scored sending Meyiwa the wrong way to make the score 3-1.
Pirates were awarded their own penalty deep in stoppage time after Collins Mbesuma was brought down in the box and it was Andile Jali who scored and made it 3-2.