Ashley Hartog, Nathan Paulse and George Maluleka scored for the visitors, with Katlego Mashego’s penalty the sole bright spark on a dark night for Swallows.
Supersport had an early opportunity when Kermit Erasmus pulled the ball back in the box, but Nathan Paulse could not find the back of the net with his pin-point header which was parried for a corner by Aubrey Mathibe.
But United did not have to wait long as three minutes later they bridged the Swallows backline. It was a route-one ball from United keeper Ronwen Williams which Ashraf Hendricks missed, allowing Sahmeeg Doutie to pull the ball back to Hartog to tap into an empty net.
Mashego had a chance to level soon after, but Williams parried his shot over the bar.
In the 26th Luvhengo Mungomeni sent in a stinging shot which Williams saved but spilt into the path of Bennett Chenene, but the young keeper got his body to the near post to deny the Swallows winger.
Five minutes after the break Matsatsantsa made it 2-0 through Paulse’s first League goal of the season. Lucas Thwala sent a long ball into the box for Paulse who brilliantly controlled with his right foot and slotted home.
United then gave Swallows the opportunity to half the deficit when Thabo September handled the ball in the box, allowing Mashego to net from the spot.
But straight from kick-off United restored their advantage when Maluleka outran the shaky Swallows defence and slotted home to make it 3-1.