For the first few rounds, sorry, minutes, it was impossible not to have the sense of a pitifully one-sided fight. You could even name one of the fighters, Muhammad Ali, representing Barcelona.
And while it may have been blasphemous to even think it, there was hardly any other way to put it. Arsenal could have been any old Joe Palooka.
Yes, they were that outclassed as Barcelona unfurled some of best of their skills. The idea that Arsenal and Barça might come together and produce one of the great European football collisions, a classic of point and counterpoint, simply withered before our eyes. Lionel Messi was an exquisite ringmaster and Cesc Fabregas was, well, just a lost boy suddenly out of his depth.
That should be an unthinkable description of the Fabregas who can so easily cut through to the heart of any game - and it certainly had to be set against his post-game revelation that he fears he was playing on a broken fibula. But it came too cruelly, too insistently last night for the peace of mind of all his admirers, who also of course include many in his home town of Barcelona. Andrei Arshavin looked peripheral, too, and he left early after injuring himself while making a tackle that blazed frustration.
However, there is a cardinal rule in the ring and on a football field or in any conflict where the decisive factors include nerve and skill.
It is to stay on your feet and do the best you can. It is not likely Arsenal did quite enough in one of the most staggering recoveries seen at the highest level of the European game to press on into the semi-finals of the Champions League at Nou Camp next Tuesday.
They will be without their captain and inspiration Fabregas, who coolly equalised from the penalty spot in the second half and rallied himself under the shadow of injury - and the fact that a yellow card meant he would miss the return.
They have to overcome the weight of Barça's two away goals and have to think only that they must win in the Catalan fortress.
It is a desperate challenge, indeed, but after they recovered from the blows delivered by Zlatan Ibrahimovic early in the second half, when he scored the two goals that seemed to announce Arsenal's disintegration, they must be given the right to believe that they might just be able to play their way out of the nightmare.
They did, after all, last night have to rebuild from the ground floor all of their highest ambitions.
It is hard, certainly, to overstate the extent of the mastery Barcelona displayed in that early going.
Arsenal were not only swept away from the centre of the ring and on to the ropes, they were rendered virtually bystanders by a style and a bite that seemed to come from an entirely different level.
They were cut into a hundred pieces, mostly by the unfathomable talent of Messi but with any number of acolytes, and most notably Xavi Hernandez, willing to help work the sweetest of combinations, there was a terrible verdict to pass on the dream of European conquest so long nurtured by the Arsenal manager Arsène Wenger.
Yet a fight is never over until the last bell rings or a man is counted out and miraculously Arsenal remained on their feet, even after those clubbing blows that came at a time when they might have felt they had survived the worst of the pressure.
You had to have belief, as Messi weaved his exquisite patterns, that Wenger had been nursing a myth these last four years since Barça proved themselves too guileful in the Champions League final at the Stade de France.
Had he also been setting himself up for a crushing fall when on the eve of battle he said that his team were going to fight the champions of European on their own superb terms?
It was the kind of promise around which Wenger has been lifting the hopes of English football for so long, not emptily but with so much football of wonderful vision and poise, but he cannot have given himself a morsel of hope for so much of this game.
Yet now he is alive again after Theo Walcott, a pale imitation of the player who struck such a dazzling figure in Croatia on behalf of England when he played last weekend against Birmingham, re-conjured something of that impact with a goal that first suggested the possibility that Arsenal might still have left a few vital signs.
And then when Fabregas stroked home the penalty that brought respect and a new hope to a team who had been threatened not so much with defeat but quite terrible humiliation, Wenger was entitled to believe that he had come through one of the worst nights of his football life with something on which to build again.
With Fabregas absent and probably William Gallas also missing next week, Wenger still faces a huge battle against the most imposing odds. He has to fear that what Barcelona threatened to produce so murderously, so early last night, with a torrent of shots and some marvellously intuitive football, will be delivered in front of their own people.
It is a possibility that can not be discounted, especially if Andres Iniesta, the missing diamond in Barça's midfield, is able to return at Nou Camp.
However, for a little while last night Wenger had no reason to believe in anything but the escape of a dark night and the anguish of an awful reappraisal of his best hopes. That denouement may still happen next week, but in the meantime there is something to hang on to a little more perhaps than the ropes.
It is, maybe, the conviction that if his team were pushed to the edge of a demoralising defeat, if they came so close to being discredited as serious rivals to Barcelona in the matter of some of the game's finest quality, they didn't forget how to fight.
They may just be able to reinvent some of their skills, but they do not have to look for new hearts, which is always a help in the toughest fights.