The Citizens claimed the win in their penultimate league match at Cape Town Stadium, courtesy of Ayanda Patosi.
Speaking after the match, McCarthy revealed that he knew the ingredients to use in order to stun his former club.
Ayanda Patosi's first-half volley guided the Citizens to a 1-0 win over the Soweto giants and they now sit at number five on the league table with 40 points and have one match left to wrap up their league season.
However, having previously qualified for the Caf Confederation, City have failed this time around to return to the continental competition.
“Before the game started I said Pirates is on good form but we have the ingredients we know how to play against them. We have beaten them the last time they were on this kind of form,” McCarthy told SuperSport TV.
“Today, tactically, we allowed them to have the ball in the areas they can’t hurt us. Also, we looked to exploit the spaces behind that is left by their full-backs and use the quality of [Ayanda] Patosi. It worked fantastically,” he said.
“I’m delighted because of the efforts of the players. They could have had nothing to play for and packed up but they wanted to give a good send off,” he concluded.
The Mother City side are now set to face AmaZulu in their final match of the campaign at the King Zwelithini Stadium in Durban.
For the Soweto giants, Pirates remained at number two behind champions Mamelodi Sundowns with 52 points from 29 league matches.
Despite their failure to steal the trophy from the Brazilians, Milutin Sredojevic has led his side back to the continent as they qualified for the Champions League.