Anderlecht 1 Arsenal 2

Arsene Wenger had wanted something to warm his cockles on the occasion of his 65th birthday and after plenty of suffering, he got it. When Andy Najar exposed Arsenal's worrying habit of switching off at the back to ignite this occasion, it had looked as if Wenger was set to add another worry line to his brow.

Make no mistake, Arsenal's Champions League future was in peril. But the response was stunning. Kieran Gibbs does not score many and he may never score a better one than the late first-time volley from Calum Chambers' cross. The connection was a thing of beauty.

But there was more. To Anderlecht’s fury, the referee ruled that there was no foul from Arsenal in the build-up to the decisive moment and, after a scramble, Alexis Sánchez crossed low and hard from the right.

The ball ricocheted inside the six-yard box before it fell to Lukas Podolski, the substitute, who had only been on the field for a matter of minutes. The German showed no sign of any rust, and he fired what amounted to virtually his first touch past the despairing Silvio Proto.

It was quite the dramatic intervention and it sparked delirious celebrations and, to a large, extent, it allowed the general torpor of what had gone before, particularly in the first-half, to be forgotten. Arsenal have a much-needed tonic.

Wenger’s birthday had provided a nice line for the occasion, with scribes duty-bound to report that he can now pick up his bus pass and the travelling supporters given more reason to chant about how he was having a party. They have a couple of suggestions about what to bring to it.

Arsenal knew that they needed to bring their A-game, which is something that has not happened with any great frequency so far this season. They arrived in Brussels having fired only in fits and starts, and to a backdrop of much soul-searching which, of course, is the standard setting of the football fan.

Anderlecht had been scarred by their previous Group D tie, at home to Borussia Dortmund, when the swell of pre-match optimism had proved misplaced.

The Germans won 3-0 and Anderlecht were left to lament a reality check and, also, the perils of over-confidence.

They were more cautious here, more measured at the outset and they settled into a first-half groove, with their speed in wide areas and up front causing problems. It was not only Ibrahima Conte on the left but the full-back Frank Acheampong – who is a defender in name only – who were asking the questions.

Wenger had stuck with the left-back, Nacho Monreal, in central defence, as he made ends meet in response to his thread-bare options at the back and the Spaniard saw his wings clipped early on when, after Alexis Sánchez had lost the ball cheaply, he was forced to check Cyriac to avoid being beaten for pace. He was booked.

There was a disjointedness to Arsenal in the first half, with Mathieu Flamini sailing close to a yellow card, as ever, and losing his bearings in alarming fashion on one occasion, when an ill-advised dummy almost allowed Anderlecht in for a chance. Despite the promptings of Jack Wilshere and the hard running of Sánchez and Danny Welbeck, Arsenal struggled to knit together much in the final third.

Their best moment of the half came at the very outset, when Sánchez beat Acheampong with a trick and cut a low cross into the area for Santi Cazorla, who had timed his arrival.

Cazorla, though, miscued his shot horribly. He also thumped a free-kick into the defensive wall after Welbeck had been tripped. The pickings were slim, and Arsenal could enter the interval pleased at having kept Emiliano Martínez well-protected. He was barely extended.

Wenger’s team enjoyed a purple patch in the second-half, when they created a brief flurry of chances, with arguably the best being when Sanchez stole unmarked onto a Cazorla free-kick in front of goal. He misjudged the header, though, the back coming off his back and allowing Proto to palm to safety.

Aaron Ramsey took a touch and shot wide while Gibbs played in Cazorla only for him to shoot weakly at Proto. Cazorla knew that he should have done better.

Arsenal looked the likelier scorers at that point but they were rocked by Najar’s header.

Chambers ought to have been tighter and Najar was allowed the time for direct his header inside the far corner.

It was the prompt for a chaotic finish. Anthony Vanden Borre scooped a shot against the crossbar after a slick Anderlecht incision while the substitute Matias Suarez was let down by a heavy touch and Steven Defour drew a smart save out of Martinez.

For Arsenal, Sánchez curled a free-kick inches wide and all seemed lost as the minutes ticked down. Gibbs and Podolski had other ideas.