Robert Lewandowski and Raphinha each scored twice as Barcelona cruised to a 5-1 victory over Villarreal yesterday in a thrilling encounter, maintaining their perfect start to La Liga.

The league leaders’ sixth consecutive win was overshadowed by a potentially serious knee injury to goalkeeper Marc-Andre ter Stegen, who was stretchered off. “I believe it’s a significant injury. When he lay on the pitch... you could see it immediately,” said Barcelona coach Hansi Flick.

Lewandowski netted Barcelona’s first two goals and later missed a penalty in an action-packed contest on Spain’s east coast, held at Villarreal’s Estadio de la Cerámica.

Ayoze Perez pulled a goal back for Villarreal shortly before half-time, and the hosts had two further goals disallowed. Pablo Torre and Raphinha added to Barcelona’s tally to seal the win. After second-placed Real Madrid’s 4-1 triumph over Espanyol on Saturday, Barcelona restored their four-point lead over the defending champions.

“It’s crucial for us to play an away game, score five goals, and, most importantly, secure the three points,” Lewandowski remarked. “In the end, it doesn’t matter how we do it, as long as we win, it’s perfect.”

Flick opted to start Eric Garcia in defensive midfield once again, despite his early red card in the midweek Champions League match against Monaco. The German coach also gave starts to reserve team players Gerard Martin and Sergi Dominguez, while playmaker Torre filled in for the injured Dani Olmo.

Teenager Lamine Yamal came close to scoring early on, hitting the post before Lewandowski opened the scoring in the 20th minute, set up by Torre. Villarreal goalkeeper Diego Conde did well to deny a close-range effort from the Polish striker, but Lewandowski pounced again in the 35th minute to score his second.

Conde made a fine save from Garcia’s header, but Lewandowski acrobatically converted the rebound from close range. Villarreal frequently threatened on the counter-attack, and Perez gave them hope after the lively Nicolas Pepe set him up.

Ter Stegen made a brilliant one-on-one save from Pepe just before half-time, but disaster struck shortly afterwards when the German fell awkwardly after catching a corner, leading to his substitution. He was replaced by Inaki Pena.

Pepe appeared to have pulled a goal back early in the second half, but his strike was ruled out for offside by a narrow margin, while Yeremy Pino hit the crossbar with a header as Marcelino Garcia Toral’s side pressed Barcelona.

Torre extended Barcelona’s lead with a deflected effort from the edge of the box, delivering a crucial blow to Villarreal’s growing momentum.

Lewandowski missed a chance to complete his hat-trick when he struck the post from a penalty after Eric Bailly fouled Yamal. Villarreal’s Thierno Barry had a goal ruled out for offside before Raphinha sealed the result, first with a deflected shot and then slotting home after being set up by a brilliant Yamal pass, leaving him one-on-one with Conde.

Despite the emphatic victory and their 100 percent start to the season, Barcelona’s title ambitions could suffer if Ter Stegen’s injury proves to be serious.