Yusuf Demir became the youngest foreign player to feature for Barcelona in La Liga since Lionel Messi on Saturday.
The Austria international replaced Martin Braithwaite shortly after the hour mark of the Blaugrana's 1-1 draw with Athletic Club.
It is the first time the winger has featured for the Catalan side since joining this summer.
What has happened?
At 18 years and 80 days old, he is the youngest non-Spanish player to represent the Camp Nou side in La Liga in almost 17 years.
Barca icon Messi was the previous youngest, having made his top-flight debut for the club in October 2004 at the age of 17 years and 114 days.
What has been said?
Speaking after the game, Barca coach Ronald Koeman suggested that Demir will learn and benefit from the experience of playing at San Mames.
Koeman said: "Demir has had a hard time in the big San Mames stadium because he's still very young, but it is very good for him to have made his debut here to begin to adapt to football of this level."
Who is Yusuf Demir?
Demir joined the Blaugrana from Rapid Vienna in July in an initial loan deal that includes a €10 million (£9m/$12m) purchase option
He impressed in his homeland after making his debut in the Bundesliga in 2019 and went on to make 38 senior appearances.
Demir got his first cap for Austria in March, coming off the bench in the last five minutes of the 3-1 win against Faroe Islands in 2022 World Cup qualifying.