Sometimes, it feels as if Sol Campbell’s entire life might be scripted by someone that was laid off from the Eastenders’ writing team. In recent times, there doesn’t appear to have been very much in his life that hasn’t been accompanied with some sort of melodrama, and this didn’t let up in tonight’s match at the Estádio do Dragão. Moreover, the match raised fresh questions over Arsene Wenger’s goalkeeping policy, as both Porto goals were, ultimately, the fault of the Arsenal goalkeeper Lukasz Fabianski and the match is now balanced on a very delicate line ahead of the return match at The Emirates Stadium.

When Forbes ranked the twenty-five most valuable football clubs in the world, Arsenal were placed third (behind Manchester United and Real Madrid), whilst Porto didn’t make the list at all. Deloitte’s annual list of the twenty richest clubs in the world sees Arsenal in sixth place, and in sixth place in their cumulative list, which has been calculated since they started the list in 2004. Ironically, that was the year that Porto last won the Champions League, but they have never appeared in this list either. Porto remain a big fish in a small pool, one of Portugal’s big three clubs alongside Benfica and Sporting. The financial disparity between them and Arsenal, is bigger than the disparity between Arsenal and, say, Stuttgart of Germany. Such is the financial imbalance in European football.

Arsenal started shambolically. Porto were playing attractive, fluid football and Campbell looked off the pace from the outset, although he did at least recover to challenge Falcao after the Porto forward had cruised past him. Soon after, Hulk shooted just wide. Arsenal were rocking, but even so the opening goal was shocking. Varela crossed from the right, but it was mishit and should have been an easy catch for Fabianski but the Arsenal goalkeeper fumbled the ball, which dribbled over the line to give Porto the lead. Manuel Almunia will probably have the best night’s sleep in the south of England tonight. It was his injury that gave Fabianski his run-out, but he will surely now be back in the team as soon as his injury allows.

Porto, however, reckoned without Campbell. Is he a man with a heightened sense of the dramatic? A robot built by Tony Warren, the creator of Coronation Street, to win bets in pubs? His return to Arsenal hadn’t been completely successful – his return match at Stoke was marked by him being out-foxed by two long balls into the penalty area which seemed to show up his ring-rustiness, but this evening he atoned for his slow start by scoring the equaliser. Cesc Fabregas sent over a corner, which Tomas Rosicky headed back across goal for Campbell to score from six yards. It wasn’t terribly good defending by Porto, but this is, if anything, slightly irrelevant. Sol Campbell, football’s current master of the dramatic entrance, was making his European debut. It was written in the stars.

Porto continued to be the better of the two sides for the rest of the first half, though. Micael forced one good save from Fabianski, but Hulk – himself banned from Portuguese football since just before Christmas pending an investigation by the Portguese Football Federation over a fight with stewards during a match against Benfica – looked unsurprisingly out of sorts. Even taking this into account, though, against an Arsenal team so stricken with injury, it felt as if Porto would never get a chance like this to put them to sword. The two sides retired at half-time level, but with both managers facing different issues to chew over.

Seven minutes into the second half, though, came the decisive moment of the match. At one end of the pitch, Rosicky was bundled over in the Porto penalty area, but the referee waved play on. Porto broke, but the ball ended up with Campbell, rolled the ball back to his goalkeeper. Fabianski, under no pressure (and somewhat inexplicably), picked the ball up. Porto acted quickly and, with the Arsenal defence not even having had the chance to get back into position, Ruben Micael rolled the ball to Falcao who stroked the ball into the corner of the net.

It was a bizarre goal and Arsene Wenger spent a good few minutes trying to argue the toss with referee Martin Hansson (he of the Thierry Henry incident – this was his first match back after that little incident), possibly that something in the exchange that had taken place between Campbell and Fabianski had been accidental, possibly about the challenge on Rosicky. He was chasing lost causes, though and, to their credit, though, the Arsenal players picked themselves up and got on with the task of trying to get back into the match. Porto, though, seemed content with their one goal advantage and, however much Arsenal threw themselves into attack with all of their energy, the brick wall of the home side’s defence was too much for them to overcome.

The media’s treatment of Arsenal recently has been odd, to say the least. Their double over Bolton Wanderers was hailed as being a sign that they were right back in the Premier League championship race, but after that they failed to beat Aston Villa, Manchester United and Chelsea in the league, as well as getting knocked out of the FA Cup by Stoke City. A narrow win against Liverpool further entrenched their place in the top four for next season, but the Champions League is their ultimate goal and there are no guarantees that Porto are going to be a push-over in the return leg. It would be foolish, however, to write Arsenal off on the evidence of a one goal deficit from the first leg of a European match. There will be all to play for in London in three weeks’ time.