Manchester City teenager Rico Lewis marked his first senior start with his maiden goal for the club as City came from behind to complete their commanding Champions League group stage with a 3-1 defeat of Sevilla on Wednesday.
City were already confirmed as Group G winners while Sevilla were assured of third spot, and Pep Guardiola made seven changes to his starting line-up, with 17-year-old right-back Lewis seizing his opportunity at the Etihad Stadium.
But Lewis, who was joined in the starting side by 20-year-old Cole Palmer, levelled in the 52nd minute when he ran on to a slide-rule pass by Alvarez and lashed home.
In doing so Lewis, aged 17 years and 346 days, became the youngest player to score on their first Champions League start, breaking the record held by Karim Benzema who was 17 years and 352 days when he scored for Lyon.
"What a goal. He's a fantastic player, so intelligent," Guardiola said. "He understands everything. He made a fantastic goal and played really well.
"In the first half the guys tried. Second half was better, really good goals. I'm happy for everyone."
Alvarez then produced a composed finish to put City ahead in the 73rd minute, taking the ball around keeper Yassine Bounou and firing into the top of the net after being played in by a sublime pass from substitute Kevin de Bruyne.
Mahrez then sealed the victory with a clinical finish after another assist by Alvarez.
City won the group with 14 points with Borussia Dortmund also going through to the last 16 as runners-up.