Barcelona were far from their best in a 3-1 win at home to Celta Vigo that kept them top of La Liga, while Lionel Messi suffered an injury scare.
Adriano, David Villa and Jordi Alba’s offside effort gave the hosts victory, with Mario Bermejo on target for the visitors, who were denied by a brilliant stop from Victor Valdes and poor officiating for the third goal.
Barcelona stay top of the standings, with Atletico Madrid needing a seven-goal win over Valencia to make up the goal difference, giving the Catalans their best-ever start to a season with 28 points from 10 matches.
A flat performance was not helped by an injury to Adriano, who was already playing out of position in a ravaged defence that started with two midfielders in central positions.
There was a late worry as Messi, who had a poor game by his standards, overextended his knee. He went off for treatment but was able to finish the match, albeit gingerly.
Early on Barcelona were superb going forward, but they left a lot to be desired defensively, their latest personnel crisis leaving midfielders Javier Mascherano and Sergio Busquets as centre-backs.
Messi’s backheel almost teed-up Andres Iniesta, but he curled the finish over, while Messi nearly chipped Javi Varas soon afterwards.
Varas was having a good game, denying a Messi curler, while from the resultant counter-attack Celta showed Barca’s defensive frailty as a desperate attempt to play offside let Iago Aspas in, Valdes saving superbly at his feet.
It was not quite end-to-end in that Barca dominated possession, but the visitors were incisive on the break.
That pattern played out in a crazy five-minute spell midway through the first half.
The opener was initiated and finished by Adriano, who rampaged forward to play a one-two with Pedro before firing home from close range.
Celta immediately drew level when, with Barca again caught short pushing up for offside, Valdes saved Alex Lopez’s initial effort but Bermejo was on hand to finish the rebound.
Their joy was short-lived though as, almost from the restart, Barca were back in front after a glorious combination of through-balls and backheels saw Iniesta release Villa, the Spain striker making no mistake with a rasping finish.
Messi was desperate to get in on the act, no doubt planning a dedication to his newborn son Thiago, and it appeared to impact on his judgement as he tried to dribble backwards from the byline to score an unlikely goal after initially being pushed wide by Varas. There were better options – such as Villa – but the Argentine was insistent on going alone.
Half-time saw a tactical switch as, with Adriano having gone off with an adductor strain in the first half, the struggling Busquets moved back into midfield as Cesc Fabregas was replaced by Marc Bartra, inexperienced but a natural centre-back.
Celta had the first chance though, as Aspas dragged an improvised low finish just wide after a clever run into the right.
Barca seemed a touch subdued by their standards but they were gifted a game-killing third by a terrible piece of officiating by the assistant referee on the hour mark.
It was a fine backheel from Villa to release Alba, but he was two yards offside, with no particular reason for confusion as the move was played at mid-pace with Celta holding a good line.
But the assistant somehow failed to spot what everyone in the stadium had – not only did Celta’s players stop, but the crowd fell silent in anticipation of the flag.
It was a dreadful miss from the officials, with the referee apparently not interested in overruling his assistant despite having been in line with the play.
That killed off any hope of a comeback, although Celta continued to work hard and chase Barca in hope of pulling one back.
The latter stages saw little action of note, although there was a delay as Messi received treatment after an uncharacteristically poor touch saw him overextend his knee.
Pedro had a late effort well-saved by Varas, but the match was long over as Barca racked up yet another win.