The 18-year-old came on as a substitute midway through the second half and made the game safe by collecting a pass from Lionel Messi on the edge of the area before cutting on his left foot and curling a wonderful effort into the top corner.
The win moved Barcelona to within two points of leaders Atletico Madrid, who will be taking on their local rivals Real Madrid on Sunday.
“Leo gave me a good pass and I don’t know how I cut and shot with the left, and thank God it went in," Moriba told Barca TV.
"I will never forget this and I will take it to my grave. There’s competition for places but it doesn’t matter if you are young or not. If you play well you’re in the team.
"The older players help us, give us advice, Leo tells me to get in the area as often as I can and get in positions to shoot.
“I want to dedicate this goal to my father and La Masia, where I have learned a lot from.”
Moriba was promoted to the senior team ahead of the 2020/2021 season after spending ten years in the fabled Barcelona academy.
He made his senior debut in January against Cornella in the Copa del Rey Round of 32 and also made his La Liga debut against Alaves in February, with the game against Osasuna just his fifth senior appearance.
