"Barca cannot make mistakes": Xavi

Samu Omorodion sent Alaves ahead in the first minute against a dire Barcelona but Lewandowski's second half double rescued the hosts three points.

The victory keeps Barcelona in touching distance of shock leaders Girona, who are four points ahead, and second place Real Madrid, who have a two-point advantage, after both won Saturday.

The coach handed Pedri his first start after injury, deployed Joao Cancelo at left-back for the first time and brought 16-year-old starlet Lamine Yamal back into the side. It took just 18 seconds for Alaves to strike.

Ilkay Gundogan lost the ball in midfield to Jon Guridi and with Barcelona's defence in total disarray, he fed Javi Lopez to cross for Omorodion, who slotted through Marc-Andre ter Stegen's legs.

"We cannot make those mistakes, it's unacceptable. We're giving far too much away and that takes a toll. We managed to get the win without playing well, that means we have a winning mentality, character, faith and courage," said Xavi.