Junior Dion struck in the 38th minute to hand Abafana Bes’thende the advantage, with Cardoso making several changes to his starting XI after Wednesday’s 2-0 win over Marumo Gallants.
Lebogang Mothiba and Siyanda Ndlovu were also brought into the line-up, with Ricardo Goss replacing Ronwen Williams.
Cardoso believes his side showed enough fight to remain confident of turning the tie around in Durban.
"We have to be stronger in the second leg and not allow Arrows three or four counter attacking chances. I believe the team was committed in this first leg, and I think the character we showed today will also come through for us in the second leg."
Cardoso believes Sundowns had established control during the opening stages before Arrows’ goalkeeper change interrupted the rhythm of the match. The stoppage lasted several minutes, and the Portuguese coach feels his players lost some of their focus and intensity during that period.
Cardoso responded at half-time by introducing Brayan Leon and Tashreeq Matthews for Bennet Mokoena and Mothiba as Sundowns searched for a way back into the contest.
The changes brought greater urgency, but the hosts continued to struggle with their execution in the final third. Cardoso also acknowledged the contribution of Mbanjwa, who made several important saves to preserve Arrows’ lead.
"Our half-time team talk was an attempt to re-organise the team and make them believe they can turn it around. Golden Arrows only had one shot on target in the game and that was the only goal, but football can be like that. Some of my players tried to adapt to the speed of the game, and the substitutes brought energy in the second half and we had a lot of shots that the goalkeeper saved."
The Sundowns coach was also asked about players such as Iqraam Rayners and Tsiki Ntsabeleng, who have found themselves competing for places in a squad packed with attacking options.
The coach says the medical team forgot to add that Rayners is not well, while Ntsabeleng still needs to show a little more in training to be included in the match-day squad.
Sundowns now shift their focus to Wednesday’s Betway Premiership clash with AmaZulu at Loftus Versfeld, before travelling to KwaZulu-Natal for the decisive MTN8 semi-final second leg against Golden Arrows at King Goodwill Zwelithini Stadium on Sunday. The Brazilians will need to overturn the one-goal deficit to book their place in the final.