Inter Milan got the better of Barcelona in their Champions League clash to severely dent their chances of making it to the knockout stages of the competition for the second year in a row.
The Catalan side arrived at San Siro needing to get a positive result after losing to Bayern Munich in the previous round.
However, they fell to a Hakan Calhanoglu first-half strike to fall third behind the Italians in the race to finish top-two in Group C.
Inter was the better side in the opening exchanges and Calhanoglu fired the first warning shot but his effort from 30 yards out was saved by Marc-Andre ter Stegen.
Angel Correa’s effort was then ruled out for offside before VAR intervened to cancel out a penalty that had been awarded to Inter.
There was no respite for Barcelona as Turkish international, Hakan Çalhanoglu drilled in the game’s first goal from outside the box after the defence failed to clear the ball.
The goal seemed to wake Barcelona up with a much-improved side taking the field in the second half.
Ousmane Dembele rattled the post in the 61st minute as the visitors showed signs of life before Pedri found the back of the net minutes later.
However, the goal was ruled out after Ansu Fati was judged to have handed the ball in the build-up to the goal.
There was more VAR drama to come in the later stages as Inter’s Denzel Dumfries seemingly handled the ball himself but after a lengthy check, no penalty was awarded leaving Xavi shouting at the refs.
The narrow defeat to Inter leaves Barcelona with three points from three games and facing the prospect of another early exit from the Champions League.
They will have to get all three points off Inter when they visit Camp Nou next week in the reverse fixture.
Bayern Munich, who beat Barcelona 2-0 last time out, top the group on a perfect nine points, with Inter second on six, ahead of Barca.
Viktoria Plzen are still without a point.
Worryingly, Barcelona have failed to score in four of their last five Champions League games.