The Brazilians took the lead through Katlego Ntsabeleng after 26 minutes, but Tshegofatso Mabasa ensured a share of the spoils with his 85th minute equaliser as he smashed home a rebounded penalty.
Cardoso’s team had failed to add to their tally, after seeing a Tashreeq Matthews goal disallowed for offsides.
The result saw Sundowns move on to 57 points from 24 games – one point adrift of league leaders Orlando Pirates, who have played a game more.
Speaking after the game, a disappointed Cardoso told SuperSport: “What happened is a game completely under control. Many occasions to make the second goal, we didn’t score.
“And a very imprudent action from us gave a penalty in the last minutes of the game.
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“We can only complain on the goals we didn’t score. I think the second half was one after the other. And when you don’t make your goal, of course, you get exposed to a mistake.
“And we did a big mistake on the approach. We were completely in control, there was no danger on that action.
“And we were reckless, very reckless the way we made that approach and we gave a penalty to the opponent. We can only complain on us, nothing more.”
Sundowns are next in action away to Richards Bay on Sunday, as Pirates take on Soweto rivals Kaizer Chiefs.