Teenage winger Lamine Yamal scored as Barcelona beat Real Sociedad 2-0 at the Olympic Stadium to move second in La Liga.
Ilkay Gundogan raced forward before finding Yamal, 16, in the box, where he coolly slotted beyond Alex Remiro into the bottom corner.
Sheraldo Becker spurned a golden opportunity to give the visitors the lead after just five minutes as he blasted over the bar from a tight angle.
Brazil winger Raphinha converted a penalty in injury time to make sure of the points after handball was given against Alvaro Odriozola.
Raphinha tried his luck from range but the former Leeds winger could only strike the bottom of the post with Gundogan unable to convert the rebound.
Sociedad goalkeeper Remiro produced a wonderful save from Raphinha with his curling shot destined for the top corner.
Xavi's side now sit second, 14 points behind champions Real Madrid, and one point clear of Girona with three games remaining.
Imanol Alguacil's men remain one point adrift of Real Betis, who currently occupy the Europa Conference League spot.