Marc Guiu, a substitute in his first professional game, scored the game-winning goal for La Liga winners Barcelona in the 92nd minute against Athletic Bilbao on Sunday.
Xavi and his Barcelona team are currently one point behind bitter rivals and second-placed Girona (after the latter’s 5-2 win over Almeria earlier today) heading into next Saturday’s Clasico.
Guiu, a 17-year-old striker, was put in by Xavi and scored less than a minute into the game, giving Barcelona the lead they needed to beat their Basque opponents.
Unai Simon got a hand to the shot but couldn’t keep it out after being set up by the smooth Joao Felix.
Barca’s La Masia academy keeps turning out talented young players, and Guiu is the latest to make his debut for the club.
With Barcelona down to the bare bones, Xavi started Inigo Martinez at the defence against his old club and 20-year-old academy product Fermin Lopez on the left of the attack.
Robert Lewandowski, a pivotal striker, is one of several players out with injuries.
As Barcelona attempted to get off to a fast start before a challenging week, Felix’s shot from a cut-back from Ferran Torres grazed the top of the crossbar.
Catalonia will play home to Shakhtar Donetsk in the Champions League on Wednesday, and will then welcome Madrid to Montjuic the following day.
Athletic, coached by former Barcelona manager Ernesto Valverde, neutralised the home team by soaking up pressure and counterattacking on occasion thanks to the presence of the Williams brothers on the wings.
After Marc-Andre ter Stegen blocked an Inaki Williams shot and parried a shot from the Ghana international, Martinez made a spectacular save to keep his brother Nico from scoring on the rebound.
Nearing the hour mark, Barcelona created their greatest opportunity, but Simon made a brilliant save from Felix’s low shot before denying Lopez from close range.
Felix then set up substitute Lamine Yamal in the area, but the 16-year-old starlet’s shot squirted beyond the near post.
Joao Cancelo was the next to force a save from the alert Simon after the teen’s arrival gave Barcelona the lead.
In the 79th minute, Xavi substituted in Guiu, and with his first touch, Guiu broke into the area and confidently shot past Simon.
Energised by the enthusiastic home crowd, the striker was shortly cautioned for a slide tackle that caught the custodian as he tried to prevent him from clearing his lines.
As a result of their win, Barcelona is now in fourth place, one spot ahead of Atletico Madrid, while Valverde’s Athletic remain in sixth.