Arsenal 4
Porto 0

Given Arsenal's notoriously schizophrenic tendencies, stumbling along blindly one moment then being brilliant the next, there were never going to be too many eyebrows raised at the idea of Arsene Wenger's men pulverising Porto on the same turf where last weekend they'd capitulated to Hull.

That Wenger's nausea from Saturday had been replaced by light-headedness at Emirates Stadium may have been courtesy of two goals apiece from Robin van Persie and Emmanuel Adebayor and some pathetic defending from the visitors.

But it was Cesc Fabregas's masterminding of this Champions League comeback victory which must have cheered him most.

For if Wenger is the composer, the young Spaniard is his principal conductor and, perhaps more obviously than at any time since he returned from Vienna as a European champion in the summer, Fabregas had the orchestra playing beautifully together last night.

"I think he was outstanding," said Wenger. "Good defensively and offensively; overall he gave a complete performance."

Clearly, he felt it was good to have the real Cesc back, the version who ran the show against AC Milan in the San Siro last season and who subsequently lit up Euro 2008 and not the pale imitation who'd been trying to shake off the ring-rust after a delayed start to the season with hamstring trouble.

When he plays as last night, he seems just about the most complete midfielder in Europe. But when he has an off day, as on Saturday, Arsenal often struggle.

Last night, there was so much else to enthuse about, from the unreal pace of the ever-developing Theo Walcott to the idea that the goals from the Van Persie/Adebayor axis could sustain another serious Champions League assault all the way to Rome.

Yet you could not escape the feeling here that Arsenal's success will be inextricably linked to the performances of their string puller and that is a lot of responsibility for someone who, it is easy to forget, is still only 21 years old.

His team-mates seem to recognise that heavy onus on Fabregas, too.

"He played well, he kept the ball as normal; Fabregas always plays good," enthused Adebayor after the game.

"Don't get me wrong, he's a human being like everyone so sometimes everything gets difficult but he is always there to show character. He is 21 and has got a lot of responsibility on his shoulders and he is dealing with that well."

Indeed, he may have returned from Euro 2008 with a new champion's mentality too, having landed his first winner's medal since Arsenal's FA Cup triumph three years earlier.

It cannot have been the easiest start to the season for him, what with his old workaholic water carrier Mathieu Flamini no longer around and still getting to know his new central midfield lieutenant Denilson, yet this felt like a statement of intent.

There were three killer Fabregas passes in the first half which alone would have been worth the admission price, the third of which wrong-footed two Porto defenders and put Adebayor in the clear in the box to cross simply for Van Persie to slide the ball home for the goal which settled Arsenal's nerves.

It was the beginning of a rout, helped enormously by defending of such shocking quality that Jose Mourinho, who won the trophy with Porto just four years ago, would have surely disowned the club.

First, Adebayor outmuscled them before half-time, heading home from a corner; soon after the restart, Bruno Alves' dithering let in Van Persie before a pointless hack from behind by Freddy Guarin on substitute Nicklas Bendtner allowed Adebayor to finish the job from the penalty spot.

Four, though, could just as easily have been eight, with Walcott and Samir Nasri guilty of misses.

Arsenal were as characterful and concentrated as Wenger had demanded that they must be after Saturday's aberration.

He had been tempted to make wholesale changes but "didn't want to give the feeling that I was punishing one more than others" so only Emmanuel Eboue had to make way for Nasri, who does look a fine acquisition.

On such an upbeat night, Wenger was not going to worry himself unduly about a few more disturbing signs of his side's discomfort at the back which could have seen them two down before they even took the lead.

Porto had hit the bar after a quick counter and also forced a goalline clearance from Gael Clichy after Arsenal's problems dealing with set-pieces — this time a corner — reared up again.

Miraculously, though, the memory of playing a team with proper defenders and battlers like Hull seemed to have already been erased.

By now, Wenger had convinced himself that, firstly, we could discount the Tigers' incredible first goal on Saturday because it was "one we have maybe all scored, but only once in our lives!".

Secondly, forget Hull's winner because it came from a corner which should never have been awarded.

Instead, he could only see how his boys were back on track having showed that they "have the potential" to win the trophy in Rome.

One suspects that potential, though, can only be fulfilled if Fabregas continues to brandish the baton with similar command week in, week out.

It is a lot to ask but, as the young maestro suggested himself last week, he needs to lead his teams to trophies if he is to be considered a truly great player.