An uplifting night...but one that showed how far Cats have to go
For Arsenal, a fairytale moment.
Charlie Patino has long been spoken about in excited whispers and even before his introduction, they were singing his name.
The goal came with virtually his first touch, the home crowd skipping home in the hope they had their 'I was there when it all started for him' moment.
"Now we have to cook him slowly," Mikel Arteta said afterwards.
It made you wonder, how will this slightly bittersweet night come to be remembered in the years to come for Sunderland?
This was the most welcome return to the big stage, a blessed break from the often arduous League One treadmill.
Over 5,000 fans arrived ready to fully embrace exactly that, and for 90 minutes they were loud and proud.
"They were just brilliant," Johnson said afterwards.
"I bumped into them on the train and in a local pub as I walked past.
"Hearing them sing all game and support the lads was great."
It has been a bumpy road at times this season but that there is broad support for this young group of players and their management is beyond doubt.
There was a striking thought in the build up to this, overhearing a young group of Sunderland supporters excitedly speculate as to who might be named in Arteta's Arsenal XI.
To a generation, the quality and glamour of the Premier League is detached almost entirely from the reality of following their club.
You were exhilarated for them, but could not help but feel a pang of regret.
Not so long ago, Sunderland were taking on this calibre of opposition every week and all things considered, it was not that long ago that they were quite often matching them in the process.
It can still, every now and then, be a little painful to feel so vividly how dramatically Sunderland's status
has been recalibrated.
As he rightly pointed out, though, Johnson can do nothing about that burden of history.
All he can do is try to set the club back on that path towards the upper tiers of the game, and it was not without good reason that even in a 5-1 defeat, he was left with a feeling of pride in players and supporters.
By the end, for sure, it had become a difficult watch.
Arteta had been able to turn to his bench for a frightening injection of quality, and a Sunderland side that has been badly affected by injury was beginning to tire.
Nicolas Pepe was irrepressible, £72 million worth of pace and clever twists and turns.
On the other flank, Nuno Tavares sensed resistance was wilting, driving into space whenever the ball came his way.
This was not, though, the story of the game in its essence. Not even slightly.
For an hour Sunderland had been within striking distance of their opponents, and at no stage did they find themselves entirely penned in.
While conceding that they would inevitably spend large spells of the game out of possession, Johnson had insisted in the build-up that they would come to play their way.
And they really did. Sure, in the opening 20 minutes it was a little frantic. The gameplan was to bank on Sunderland's undoubted technical quality, and speed in the frontline, to quickly break when winning the ball.
To start with they went a little early, but they did find gaps throughout and Arteta admitted his side had been lacking cohesion.
The frustration was that when Arsenal broke through, it was from a setpiece. A goal not about a gap of two divisions, but simple defensive organisation.
But it did make the response that followed the second goal all the more impressive, for at that point it looked for all the world that after a steady start Johnson's side were staring down the barrel.
With every passing game, Sunderland's new playing philosophy is beginning to look a little more embedded.
It bodes well for the long term that even against this calibre of opponent, it was on show. And how. First the awareness of Dan Neil to snap onto a second ball. The clever 1-2 with the excellent Alex Pritchard, and the first time pass to open up the pitch for Elliot Embleton.
Then, it was all Premier League. The drive into space, the inch-perfect through ball. The audacious firsttime finish from Nathan Broadhead. The roar from the away end, limbs flailing, hopes growing.
It was some moment. To Sunderland's credit there were nearly a couple more.
In a superb end to the first half, Carl Winchester almost levelled the scores, and even after Arsenal's third, Embleton almost produced a stunning effort to reduce the deficit once again.
Throughout, the Black Cats tried to press high rather than sit in.
At times it cost them, but those present were clearly buoyed that their side had come to have a go.
It was, Johnson said, the most valuable learning experience a broadly young group of players could hope for. On the ball, there were times when the level did not look beyond them.
Off it, there were times when the gulf was exposed.
Take that outstanding fourth Arsenal goal, for example. The speed and precision of Martin Odegaard's pass, the run of Eddie Nketiah and the ruthless firsttime finish.
There was another fairly simple reality here, too.
In the wide areas Arsenal were simply too strong, too quick, and little wonder.
There have been occasions where Sunderland's lack of orthodox options in the full/wing-back position have left them looking exposed against League One opposition.
That Arteta's side found so much joy creating overloads with their attacking quality was perhaps inevitable. All told, it was fundamentally where the game was won and lost.
Sunderland's campaign has been significantly simplified, now. A 24-game dash in League One, with no cup distractions.
The platform is there, but the January window will be key.
This is a side who against any opponent will create chances and score goals, though the injury to Broadhead was the night's biggest negative by some distance and will demand further business.
There are defensive issues, though, both in terms of depth and attributes and if Johnson is to steer his side into the top two then then they will need addressing.
This was an uplifting night, a genuine thrill to see so many talented young players grow into the stage and to see the travelling red-andwhite army respond with such typical ferocity.
Arsenal's quality, for sure, showed how long the road back to this level is for Sunderland.
If that feels a little daunting at times, then there was also comfort in seeing that this group has a lot going for it as it bids to take those first steps.
Now it is about getting out of League One and nothing else.
Manage that, and the night of Patino's arrival might come to be seen as one where a proud club took another step in its rebirth.
Whatever comes next, we'll always have that goal, those seconds the ball drifted slowly but surely towards the line.
A move to grace any ground.
There is a platform here, without a doubt. Now it’s time to build on it.