Davies Mwape and Lethola Mofokeng scored for the Ezenkosi, while Elias Pelembe netted for Matsatsantsa.
Cosmos dominated for most of the first half, which was a pretty dull affair.
The only chance in the first half came in the 33rd minute when Supersport were awarded a penalty after Lucky Mhlathe handled the ball in the area, but Katlego Mphela’s spot-kick was saved by Avril Phali.
The match remained goalless at the break.
Cosmos continued their dominance in the second half and deservedly went ahead in the 53rd minute when Mwape ran outstripped the Supersport defence to slot home with a powerful shot from inside the area.
The visitors almost equalised a minute later, but Daine Klate’s volley was tipped over by Phali.
Supersport then stamped their authority on the game and equalised in the 66th minute when Pelembe scored at the far post following superb work by substitute Katlego Mashego.
However, the visitors’ joy was short-lived as the Ezenkosi regained their lead six minutes later with a superb strike by Mofokeng.
Mofokeng could have extended Cosmos’ lead in the 84th minute when he broke clear, but e was pulled back by Senzo Ndlovu, who received his marching orders for the offence.
Cosmos will be looking to build on this result when they take on Ajax Cape Town at Athlone Stadium on September 16, while Supersport will be looking to get their season back on track when they host Kaizer Chiefs at the Super Stadium on the same day.