Bafana Bafana defender Morgan Gould was shown a second yellow card on the hour-mark, with United leading 1-0 at the time courtesy of Glen Salmon.
Swallows made the most of their fortune and levelled matter on 70 minutes through Macbeth Sibaya, but for all their efforts they could not get the second goal.
The opening goal came from nothing in the 15th minute when Dipsy Selolwane took a shot from outside the box that was going across Greg Etafia’s goal, but Salmon showed good anticipation and skill to flick it past the goalkeeper with a neat backheel.
Swallows started pushing forward in search of the equaliser, but their first chance came in the 29th minute when Joseph Makhanya received a pass from Lefa Tsutsulupa on the right, but his strike sailed wide of goal.
The Dube Birds had another chance eight minutes later when Bennet Chenene tested Ronwen Williams with a long-range shot, but the young goalkeeper blocked the attempt and reacted quickly to gather the rebound before Ashraf Hendricks could pounce.
A minute later it was Makhanya who twisted and turned the defence on the right before rifling a shot from an angle which Williams tipped over the bar.
The visitors were reduced to 10 men in the 61st minute, but they almost increased their lead five minutes later when a long kick from Williams found Atusaye Nyondo; the Malawian fired a shot on target, but Etafia did well to block it.
Swallows had their own break immediately after that when Tsutsulupa released Siyabonga Nomvete on the right but the veteran striker drilled his shot over the crossbar. The Birds came close again in the 73rd minute when Nomvethe played the ball across the six-yard area, but substitute Mpho Maleka arrived a second too late.
The equaliser arrived two minutes later when Swallows won a free-kick just outside the box; Tsutsulupa rolled the ball towards Sibaya, who fired a powerful shot which picked up a deflection on its way into the back of the net.
Swallows had a few more chances to grab all three points, the best of them falling for Maleka in the 93rd minute, but the former Aces man pushed his shot wide.