Lewis Koumas made the step up to the U21s and scored twice for Liverpool in victory over Stoke City on Sunday.
The U18 regular looked comfortable at his new level, hitting a brace and playing a full 90 for the 3-1 win.
Fellow FA Youth Cup attacker Jayde Danns also played a full 90 as coach Barry Lewtas led his attack with the two U18 strikers.
Also scoring for Liverpool was Amara Nallo, who joined from West Ham earlier this season.
Senior pair Kaide Gordon and Bobby Clark also started on the day.