WATCH: Xavi's game plan flies out the window! Barcelona concede just 17 seconds after kick-off against Deportivo Alaves as Samuel Omorodion finishes off sweeping counter-attack

Barcelona conceded just 17 seconds after kick-off as Alaves forward Samu Omorodion broke the deadlock. Ilkay Gundogan gave away possession cheaply to Jon Guridi, who initiated a run from his own half before finding Javi Lopez with a pass. Lopez then squared the ball for an unmarked Omorodion, and he casually pushed the ball into the net.

Omorodion could have doubled his team's lead in the 31st minute when he found himself one-on-one with Marc-Andre ter Stegen after he received a pass from Guridi, but the striker blasted the ball over the crossbar.

The Catalan giants bounced back with a brace from Robert Lewandowski to turn the match around in the second half. Barca will be back in action against Rayo Vallecano after the international break.