Salaheddine Saidi broke the deadlock on 26 minutes for Wydad but Anele Ngcongca then drew his side level before the break.
However, a defensive lapse just after the half-time interval allowed Wydad to claim the win which did not exactly please the Sundowns mentor.
“While I’m not entirely happy with the result because we lost 2-1, I’m happy with the performance from the team because it’s difficult always a place for us here in Morocco but we improve,” Mosimane was quoted as saying by the club’s official website.
“We made a lot of mistakes at the back, but you have to understand that everyone is stressed because it’s the Caf Champions League semi-finals and everyone wants to go to the finals. I believe we should have cleared the ball in the first goal,” he added.
While Wydad may have a slender advantage heading into the return leg set for Tshwane, Sundowns are perhaps slight favourites thanks to the vital away goal.
“It was the first time I see Wydad so stressed at the back, it’s also because we scored the important away goal,” he concluded.
Heading into the game, Sundowns boast an impressive home record in the Champions League as they are unbeaten in their last 12 games.
Before they can turn their focus to the second leg though, they will need to keep up the pursuit on Orlando Pirates in the Premier Soccer League (PSL) when they take on Black Leopards in an all-important encounter in midweek.