Ayyoub Bouaddi belied his age with a mature Champions League performance on his first Manchester City start to showcase why the club were so intent on signing the 18-year-old.
The midfielder took centre stage for Morocco at this summer's World Cup and City spent £86m to sign him from Lille, making him the most expensive teenager in Premier League history.
And after two substitute appearances for City, he was handed his first start against Porto and did not look out of place during the 2-0 victory.
Erling Haaland will take the plaudits for his two goals, but it was Bouaddi who caught the eye with a tidy and assured performance in the middle of the park, signalling early signs that Rodri may not be too sorely missed after his departure.
"His age, his game – he looks absolutely born to do it," former Chelsea winger Pat Nevin said on BBC Radio 5 Live during the game.
"I cannot take my eyes off Bouaddi, he looks very special. The City fans had the fear of losing Rodri - I watched Bouaddi playing against Scotland at the World Cup, he has been very impressive so far.
"Bouaddi is an absolute no-brainer. He is brilliant. You get him at that age and you don't think he might work, he is a class act."
Aged 18 years and 341 days, Ayyoub Bouaddi became the fourth-youngest player to start a Champions League match for City.
Question marks were raised around the size of the fee for a position on the pitch where players can be exposed, but Bouaddi seems to have settled in immediately and showcased why he will be a valuable option this season.
"He is very good," said manager Enzo Maresca. "Against Coventry, he lost two balls and after that he was inside our box and calm. Other players may have panicked but at 18, he is a fantastic player.
"Tonight, he was very good. He speaks French, English, Spanish perfect. He is different in how mature he is. This is why the club has made the effort for him to be with us."
BBC Sport reported City's interest in Bouaddi in June and, contrary to reports, sources said signing him and then loaning back to Lille for a season was not on the agenda.
The performance in Portugal highlighted why those in power at City believe he has all attributes to "develop into a world class talent" and he clearly enjoys playing on the biggest stage.
Two years ago, Bouaddi earned a standing ovation from Lille supporters after helping his side to a shock group phase victory over holders Real Madrid and the travelling City fans will have been doing the same in Portugal on Tuesday evening.
Bouaddi completed 54 of his 55 passes, while he also topped the metrics across players of both sides for most dribbles (4), most times possession won (7) and contesting more duels (13).
"He did a really good game," said Haaland. "The last couple of weeks in training, he has been amazing. I think we have got a gem there, to be honest."
Though it was only Bouaddi's 10th appearance in the competition, the Norwegian sent a playful yet pointed message to his team-mate about needing to be perfect all of the time.
The striker added: "I think he should've played me through in the second half so I was a bit angry.
"But he played a good game... except for that pass."