Bucs were targeting nothing but a win over Siwelele having recorded their second successive league victory when they defeated Lamontville Golden Arrows 1-0 in Durban over the weekend.
Abel Mabaso was handed his full debut by Serbian coach Milutin 'Micho' Sredojevic, who also included former Celtic defender Alfred Ndengane in the starting line-up.
Siwelele were keen to complete a league double over Pirates having extended their winless run to three games in the league when they drew 0-0 with Mamelodi Sundowns in Tshwane over the weekend.
Mzwanele Mahashe made his return to the Celtic starting line-up - replacing fellow defender Wandisile Letlabika, who picked up a serious head injury during the clash against Sundowns.
The Buccaneers dominated possession in the opening stages of the encounter with Musa Nyatama, who was also facing his former club, pulling the strings in the middle of the park.
However, they found it difficult to break the Phunya Sele Sele defence which was marshalled by Mahashe, who made crucial clearances from the visitors' area.
Siwelele grew in confidence as the match progressed and they managed to break the deadlock after Pirates were caught ball-watching inside their own box eight minutes before half-time.
A ball was played into the Bucs box and Rikhotso pounced and fired past goalkeeper Wayne Sandilands to make it 1-0 to Celtic - stunning the home crowd into silence.
Celtic then held onto their narrow lead and they were leading 1-0 at the interval with Pirates having failed to seriously test Patrick Tignyemb in the visitors' goal.
Pirates came back rejuvenated after their half-time team talk with Micho and Tignyemb became a very busy man as he produced two magnificent saves to deny Shonga.
The former Cameroon under-23 international pushed away Shonga's headed effort, before tipping the Zambian marksman's goal-bound free-kick over the crossbar.
Micho then introduced Memela, who grabbed a goal and an assist against AmaZulu FC, and Arrows respectively last week, as the Buccaneers looked to snatch a late equalizer.
Memela proved to be an inspired substitution as he netted in the 80th minute to make it 1-1 and it was not surprising as Bucs had netted the majority (25%) of their goals in the final 15 minutes of their league games this season.
Pirates then pushed for a late winning goal, but Tignyemb was in top form as he pulled off great saves to deny Thabo Qalinge and Vincent Pule to ensure that the game ended in a 1-1 draw on the night.
Despite the draw, Bucs climbed to the top of the league standings on goal-difference after Sundowns lost to Cape Town City, while Siwelele remained eighth on the table.