Goals from Brayan Leon (25', 60'), Teboho Mokoena (32'),Tashreeq Matthews (51') and Bennet Mokoena (90+1') sealed the win, with Thandolwenkosi Ngwenya (46', 70') netting twice for Usuthu.
Four Sundowns' players were yellow carded during the match, compared to one for AmaZulu, and Cardoso feels that his players are being unfairly targeted.
"I'm not happy seeing my players seeing so many yellow cards," the coach said on iDiski Times.
"It's important that we understand that we have already in six matches, 15 yellow cards, a team like Sundowns that dominates matches after matches, go see the stats and ball possession.
"We finish with four yellow cards, AmaZulu with one, against Golden Arrows we had three, they had one – we played Marumo, one yellow card, Marumo with zero, Chiefs four-four, Polokwane two-two, but Polokwane should have had three yellow cards," Cardoso added.
"Last year we had 53 yellow cards, Pirates had 28, we had four red cards, Pirates had zero red cards," he said.
"The yellow cards put players out as we go through the season and these matches will speak for the championship [title].
"I speak for the referees, pay attention in the way you are easily targeting my players because it's too easy to target my players. When I received my yellow card I said it's too easy to target my players," Cardoso mentioned.
"We play positive football, with respect. Just understand the role and the way we respect football, we're not a bad team or bullies inside the pitch, we want to play the game.
"We want our players to play as much as the players against the teams we fight against – the rules are the same for everybody," concluded the Brazilians' boss.
