Fermin Lopez, an academy star came on as a substitute and immediately scored against Sevilla but was then sent off in a wild appearance.
Barcelona took the lead against Sevilla within seven minutes through Robert Lewandowski, and at the end of the game the scoreline was 4-1 in favour of Barca.
Sevilla equalised the first goal within 1 minute.
At half-time, coach Hansi Flick replaced Gavi with Fermin Lopez through a substitution, Fermin added a second goal with his first touch, attacking a ball into the back post and heading into the bottom corner.
Afterwards, Djibril Sow approached the referee for a penalty after going down in the box but Barcelona broke quickly and Raphinha scored a brilliant goal from a long range.
As the hour mark ticked by, Fermin was sent off after an awful lunge on Sow; he was initially shown a yellow card but VAR recommended that it be upgraded to a red card.
Eric Garcia, who came from the bench, made it 4-1 in the last minute with a back-post header.
