Manchester City began their Champions League campaign with a convincing 2-0 win over Porto at the Estadio do Dragao.
Haaland struck twice in the second half to settle it. But the eye-catcher was Morocco's Ayoub Bouaddi, who lit up midfield on his first start.
Just 18, he ran the show. He completed 54 of his 55 passes and won the ball back seven times before Mateo Kovacic replaced him in the 76th minute.
Enzo Maresca could not hide his delight at the collective grit his side showed on a tricky European away night, and he pointed to the quality and depth of his squad.
The Italian gave his verdict to Amazon Prime: "I think we were able to score more goals, especially in the first half, but overall I think we deserved to win the game."
He added: "We created enough chances to win the game. We didn't concede many goals. It's normal to give up a few chances here, so I'm happy with the performance overall. I think I'm fortunate that all my players are good, and that makes it easier for the coach because he can give them all minutes, and I think the players who featured tonight were excellent."
Maresca then turned to Bouaddi's composure on the big stage. He called the youngster's display stunning, admitting he had not expected him to handle the occasion the way seasoned pros would.
He stated: "The good thing is that you expect Haaland, Ruben Dias and Mateo Kovacic to know how to manage this game, but Ayoub Bouaddi was never flustered. He was very good, and I think the performance was stunning."