With this defeat, Petro de Luanda makes it difficult to reach the final of the tournament.
Tiago Azulão, in his own goal, in the 16th minute, gave the Moroccans the advantage, who increased it in the 45th, by Yahya Jabrane, and Guy Mbenza, in the 68th minute, made it 3-0. Petro de Luanda reduced through Job, at 81.
The second leg will take place on May 13, in Moroccan territory.
In the other semi-final, Egypt's Al Ahly thrashed Algerian Antant Setif 4-0 at home.
The coach of Petro de Luanda, the Portuguese Alexandre Santos, acknowledged this Saturday that the home defeat by 3-1 against Wydad Casablanca compromised the emblem's ambitions to reach the final of the African 'Champions'.
"Today's result complicates our aspirations to reach the final. We are at a big disadvantage for the second leg and I know it will be very difficult, because we know which team we will face in front of their audience", said the Petro coach.
The coach of the Moroccans of Wydad Casablanca, Walid Regragui, admitted that the mistakes made by the Angolan team were decisive for the victory of his team in Luanda.
"We knew that Petro de Luanda likes to play 'tiki taka' and we had a strategy of letting them play and going over their mistakes. And, simply, that strategy worked very well for my team. but I have to say that Petro are a very strong team and we didn't expect to win by 3-1", said Walid Regragui.
In turn, the Minister of Youth and Sports expressed confidence in Petro de Luanda's qualification for the final of the African Football Champions League, despite the defeat in the first leg of the semi-finals of the competition.
"If the opponent came to our house and scored three goals, I am convinced that we can also do the same at their house", said Ana Paula do Sacramento Neto, appealing to the Angolan people to believe, despite the second leg being played out on the grounds of WAC Casablanca, in Morocco.