Lamine Yamal scored his first La Liga goal of the season as Barcelona battled to a narrow win over Athletic Bilbao at the Olympic Stadium.

The 17-year-old Spain winger put Hansi Flick's side in front in the 24th minute with a curling shot from outside the box which deflected off the head of Athletic defender Inigo Lekue.

Athletic got themselves back on level terms when they were awarded a penalty a minute before half-time, after Pau Cubarsi felled Alex Berenguer inside the box.

Oihan Sancet confidently sent Marc-Andre ter Stegen the wrong way from the resulting spot-kick.

Robert Lewandowski, who scored both goals in the Catalan club's 2-1 win over Valencia on the opening weekend, got the winner with 15 minutes to go.

The Poland striker had twice hit the post from good positions earlier in the game but secured the points with a classic poacher's goal.

Pedri's low cross was parried by visiting goalkeeper Alex Padilla and Lewandowski pounced on the loose ball to hook home from close range.

Barca's victory maintained their 100% start to the season in La Liga, with champions Real Madrid hosting Real Valladolid at the Bernabeu at 16:00 BST on Sunday.