The teenager, who made his Barca debut in last week’s 5-2 win over Real Betis, headed home a cross from Carles Perez in the 51st minute.
Barcelona’s 16-year-old forward Ansu Fati became the youngest ever player to score a league goal for the club when he netted an equaliser for the La Liga champions at Osasuna on Saturday. Barcelona have only won one of their last eight games without Lionel Messi.
The teenager, who made his Barca debut in last week’s 5-2 win over Real Betis, headed home a cross from Carles Perez in the 51st minute, having come off the bench at the start of the second half with his side trailing promoted Osasuna 1-0.
Fati, who turns 17 on Oct. 31, replaced Bojan Krkic as the club’s youngest scorer in La Liga and is the third-youngest player to score a goal in Spain’s top-flight behind Fabrice Olinga and Iker Muniain.
Roberto Torres’ thumping volley gave Osasuna the lead in the seventh minute to send the boisterous El Sadar crowd into a frenzy and Barca struggled to cope with the home side in a first half in which they failed to have a single shot at goal.
Coach Ernesto Valverde turned to Fati at the start of the second period and the teenager needed only six minutes to get off the mark, rising to head home a cross from fellow academy graduate Carles Perez.
Barca took the lead in the 64th minute through a superb strike into the bottom corner from Arthur Melo but Osasuna were given a way back when Gerard Pique handled in the area and Torres made no mistake from the spot to equalise in the 81st.