The result on the night shows they won 2-1, while the Group G table has them top after three wins from three games, but Barcelona's victory over Celtic in their Champions League clash at the Nou Camp was anything but straightforward.
Barca had nigh-on 30 attempts on goal against the Scottish champions, but it took one moment of inspiration, rounded off by Andres Iniesta, and a defensive lapse for Jordi Alba's winner at the of each half to spare the Catalan side's blushes.
But the problem for Tito Vilanova's side was not in attack. It rarely is. After all, they were up against a Celtic side who were admirably disciplined and organised, who adjusted brilliantly from their 5-0 win at St Mirren at the weekend in front of 6,000 people to a marquee fixture with 75,000 present and millions watching across the continent and beyond.
Celtic manager Neil Lennon had twice contributed draws at the Nou Camp for the Bhoys as a player eight years ago, and he was so close to achieving such a result again as the club's manager.
Barca's big issue was at the back. With both key centre-backs—Gerard Pique and captain Carles Puyol—missing through injury and defensive midfielder Sergio Busquets suspended, the Blaugrana's defence was certainly a patched-up back four. Converted midfielder Javier Mascherano—all 5-foot-9 of him—was again leading the line, ushering young defender Marc Bartra through just his 10th senior appearance for the club.
Not only that but Adriano—who was deployed almost exclusively as a left winger during his time at Sevilla—was filling in at right-back in the absence of Dani Alves.
Celtic took a shock lead with their only effort on goal in the first half which, predictably enough given the circumstances, came from a set piece. Mascherano leapt for Charlie Mulgrew's well-delivered free-kick, but Georgios Samaras outjumped his diminutive marker without barely leaving the ground to nod home the opener 18 minutes into the first half.
Perhaps Celtic scoring was not that much of a shock at all. In their last three league games, Barca have scraped a 3-3 win at Sevilla with two late goals, looked unconvincing as they drew 2-2 at home with Real Madrid and, last weekend, won by the odd goal in nine at Deportivo La Coruna.
Barca's belief that they can always outplay the opposition is in danger of stretching too far. Clearly, this is not the defence Vilanova would have chosen to field, but their eschewing of signing any more specialist centre-backs as cover for their two world-class first-choices has been exposed as foolhardy at best and arrogant at worst.
Puyol and Pique are two of the game's finest in their position because they are as talented with the ball at their feet as their teammates further up the pitch, but they are defenders first and foremost.
Mascherano has made the transition to defence admirably well, but a club of their stature should not be resorting to such stop-gap measures on such a regular basis. The attempt to repeat the trick with Adriano was easily exposed against Real Madrid.
That Bartra—a 21-year-old with fewer than a dozen senior games under his belt—made more tackles (five), more clearances (five) and interceptions (three) than Mascherano (3, 2, 0) shows the importance of making selections with regard to relevant attributes rather than overall quality.
Save for dipping into their B team again, Barca have little choice except to continue to persevere with their makeshift back line whenever the situation demands it until the January transfer window at least.
They remain unbeaten in La Liga and Europe this season, but they have already had their fair share of fortunate escapes. That luck cannot keep going indefinitely.
Perhaps, in perverse way, losing to Celtic would have actually been more beneficial for them. The problem would have been far more stark, and the actions to address it more urgent. There would still have been three more matches with which to top the group, potentially still with a game to spare. By avoiding defeat, the feeling that the status quo can be maintained still lurks.
The major reason for that is because Barca remain such a sublime attacking force. The quick interchange of passes between Iniesta and Xavi which led to the former's equaliser in the 45th minute was as mesmeric as any goal scored under former coach Pep Guardiola, as were their offensive statistics. They had 28 efforts on goal with 10 on target, 82 percent possession, 93 percent pass completion—you know the drill.
But every time Celtic won a set piece in the Barca half or launched an unsuccessful counterattack, the nagging sense that Barca were vulnerable prevailed.
One final piece of fortune, which may well be their saving grace, is that they do not face another genuinely top side in La Liga until mid-December, when they host high-flying Atletico Madrid and their star striker, Radamel Falcao. The media may well be fuelling speculation about a possible move to the Nou Camp for the Colombian goal machine in the build-up to that clash, but Barca's full attention must be focused on augmenting their defensive options as soon as possible.