A first-half goal by debutant Fiston Abdul Razak saw Siwelele taking the lead, however, Stuart Baxter’s men pulled one back through defender Luvolwethu Mpeta to ensure both sides shared the spoils.
Serame Letsoaka’s men started like a house on fire in the opening five minutes and Razak received a great pass from Lyle Lakay, but the lanky Burundian missed as his shot went over the posts.
Despite good football, the first 10 minutes had no clear-cut scoring opportunities, with Siwelele having to adjust to the windy conditions.
However, after 20 minutes of action, goalkeeper Patrick Tignyemb produced a brilliant save to deny Thuso Phala after a good build up with Dove Wome.
Despite being starved of the ball by Baxter’s men, Phunya Sele Sele managed to grab the lead through Razak with seven minutes to go to the interval.
A set-piece from Lyle Lakay on the left saw Razak rising alone in the box to head home, beating Ronwen Williams.
Two minutes after the break, United had a chance to score when Wome tried an acrobatic kick in the box but it was cleared by Alfred Ndengane.
Just after the 51st minute, referee Victor Gomes stopped the match due to lightning, however, he then decided to continue.
Following the short break, Musa Nyatama saw his shot being saved by Williams for a corner after a wonderful cross by the speedy Morena on the right.
After a number of attempts to keep United at bay, Celtic finally cracked when Mpeta scored in the 62nd minute.
The ex-Platinum Stars man made a fantastic run down the left flank into the box, beating a number of defenders before slotting the ball into the net, 1-1.
In the dying minutes of the tie, Siwelele’s Morena continued to trouble United as he received a pass from Razak from the left but his shot went wide of the far post.
Nevertheless, in injury time, Williams was awake to deny Lakay from a set-piece.