Thierry Henry erupted, briefly but beautifully, and so of course suddenly there was hope. Suddenly Arsenal were alive again, for a little while at least. That they made something of a fight of it against a much more committed Bayern Munich was because they had been given the oxygen of genius.
Yes, it is a word too liberally thrown at some of the luminaries of the modern game. But then when we see the evidence we should not shy away. It was impossible to do so when Ronaldinho unfurled an astonishing goal at Stamford Bridge on Tuesday night. The one Henry scored in the 66th minute here was not of the same order of fantasy, but it was perfect in every way.
It was perfect in first touch, in control and in finishing certainty when Ashley Cole, sensing a growing desperation around him, slung down a long ball in the path of Henry.
This was the essence of Henry, the sublime goalscorer facing a growing crisis of doubt about his ability to deliver the best of his talent when it matters most.
Before his superb goal Henry seemed implicitly to acknowledge the pressure on his shoulders. He covered the ground, quite ferociously at times, and he offered that desperately needed diet of hope. How much of it could be sifted from the overwhelming authority Bayern established in the first half was not easy to say, especially with Arsène Wenger frantic again on the touchline and racking up several more years of psychological wear and tear in the course of a single match.
But then when Henry makes a move, however fleeting, the mystery of Arsenal's decline, at least the depth of it, always seems to be on the point of banishment.
No one in football makes anything look quite so easy; the dimensions of the field are suddenly slashed, and so it was just before half-time when we heard the first awakenings of Arsenal belief. Henry smoothly gathered in a rebound off the shin of Robert Kovac and bore down on Oliver Kahn, the eccentric but still workably obdurate German goalkeeper. Kahn stifled Henry's shot but he could not wipe away the effects of the Frenchman's intervention.
It was the clearest evidence that Henry remained far and away the most significant catalyst of Arsenal's surviving hopes for the season which began to drain away with that devastating defeat at Old Trafford last October.
When he made his run along his favourite terrain of the left, when he wore his intensity on his face and injected it into every small phrase of his body language, Highbury did suddenly believe again. However, it was a perilous yearning, buffeted constantly by the swarming work of the men in black.
On the eve of the match Henry released an extraordinary stream of consciousness when dealing with the growing belief that football history may judge him harshly when it weighs the size of his talent and the slightness of his achievements on the biggest occasions. He said that Thierry Henry and Arsenal were indivisible, you could not judge one without the other. He said it with great intensity, as well he might.
Last night, however, we did see that division clearly enough. We saw an Henry who, for one reason or another, chose to wear the fact that he cared like a battle flag, and we saw an Arsenal, uninspired but slowly biting into the match, truly fighting for their lives in Europe, the theatre of action where they have consistently betrayed themselves.
That they found the will to do this was, who knows, perhaps because so much expectation had been placed on the shoulders of Henry, a star surely, but also a warrior? But whatever the explanation, there was one certainty. It was that Henry had come to play, to fight for his reputation and the life of his club as a serious force in English and European football.
That was something to take from the night Arsenal again failed to make their mark in Europe. They lost the game but Henry, at least, retained his honour.