Ilaix Moriba made his Barcelona debut on Thursday as Ronald Koeman's side required extra-time to beat Cornella 2-0.
Ousmane Dembele and Martin Braithwaite score in the additional 30 minutes after Dembele and Miralem Pjanic has missed penalties in normal time.
Ilaix, 18, started the game, making his first-ever appearance for the senior side before coming off with 20 minutes to play.
"It's an amazing feeling," the teenager said after producing a good display and looking comfortable in the Barça midfield.
"Since the coach (Ronald Koeman) told me I was going to be in the side today it's been... good. I got home and I couldn't sleep.
"I am really happy at the club, especially with the coach, very grateful, and also with all my teammates who made it possible for me to play well."
So what now?
"I just take it day by day," he added. "It's the club who tell me up (first team) or down (B team). I have to do my own thing and be aware that I am a B team player, with Pimi, who I am very grateful to, also to Catena, Franc, Marc Serra."
Ilaix celebrated turning 18 on Tuesday and he said "this is the best present I could have and I am so grateful to Koeman."