La Masia prospect Marc Guiu scored the only goal of the game as FC Barcelona registered a 1-0 win over Athletic Bilbao in their La Liga fixture on Sunday. The 17-year-old Spanish forward replaced another fellow youngster Fermin Lopez in the 79th minute and struck immediately to give the Catalans the lead. Guiu's goal means he has scored his first league goal for Barcelona quicker than any other player in the club's history. Victory takes Xavi's side back within a point of leaders Real Madrid, who they face next Saturday.