Arsenal may just have discovered the difference. It is not necessarily about signing another forward to match Paris Saint-Germain’s level, but about their existing attackers producing at the standard they are truly capable of.

More than anyone else, in so many respects, that means Martin Odegaard. Over the last few weeks, the playmaker has looked nothing like the version seen last season. And this decisive goal away at Napoli was exactly the kind of moment that was so often absent in the previous campaign.

His superbly angled strike in the 75th minute, drilled in off the post with real force and precision, perfectly captured that shift. A match that had been rather sluggish, and brought back memories of some of Arsenal’s more heavily debated performances from last season, was transformed into something very different.

Martin Odegaard scored the only goal to underline his growing importance to Arsenal.

It was another champions’ win, and also a near-flawless opening to their Champions League campaign, extending their perfect start to the season. They now have a 100 per cent record, with their captain looking completely sharp again.

That, in itself, deserves a much bigger conversation, especially given the many discussions that specifically surrounded Odegaard last season.

For the moment, though, it sharpens the wider conversation around Arsenal. That perhaps they have finally arrived. That they are ready to become European champions, having already become English champions.

Arsenal may finally be ready to become Champions League winners.

If the obvious message to Mikel Arteta is that it is not how you start but how you finish, given last season — and perhaps also some of the wastefulness in this game — he knows that the near-miss in Budapest was really about the full journey; about constructing a squad that is complete, balanced and whole.

That is why they pursued Vinicius Junior and Julian Alvarez, in an effort to add elite forwards comparable to PSG’s. Even so, those additions were intended more as finishing touches than fundamental repairs.

Odegaard remains the centre of it all, the player who binds everything together and around whom the rest of the side is meant to function.

And with him at the heart of it, Arteta appears to feel that his team are now right in that top bracket. Yes, up there on overall quality terms with PSG, Bayern Munich and Barcelona. Within the club, there is a belief that, just as with finally winning the Premier League, it comes down to the finest details and the smallest moments.

And, crucially, to keeping players like Odegaard fresh.

Odegaard has reached new levels and Arsenal must now keep him fresh.

The feeling within Arsenal and other major clubs last year was that PSG — and arguably Bayern Munich — often carry an advantage because they usually enter the biggest matches with all of their best players available and none of them burdened by fatigue.

Many will have noticed the statistic from this week that seven of PSG’s Ballon D’Or nominees played less than 50 per cent of their league minutes. Arsenal plainly cannot operate in that way, and can only try to reproduce the same effect by other means.

They need to maintain a competitive consistency without relying on exactly the same team every time.

That may be easier said than done, because those who know Arteta say one of his clearest idiosyncrasies is his determination to try to win every single game.

That is why Declan Rice has featured in virtually every match and why, at the same time, Martin Zubimendi is now finding himself on the sidelines far more often.

Mikel Arteta is evolving as Arsenal manager.

Zubimendi was hardly ever out of the side until April last season. Fatigue was entirely understandable, and it has helped create space for Myles Lewis-Skelly’s increased prominence.

And yet the absence of both from the starting line-up may have hinted at another stage in Arteta’s evolution, matching the way he finally eased off on training during last season’s run-in.

In similar fixtures last season, his staff would have expected Arsenal to go all-in for a game like this, especially as it was the first match of the Champions League campaign and a glamour tie as well. Instead, Arteta rested almost half of his first-choice outfield players.

The only real surprise there was Bukayo Saka starting, when it had been expected that Noni Madueke would come into the side.

Bukayo Saka unexpectedly started the match, although he missed a golden opportunity.

Saka only occasionally lifted the quality of the contest, and he should have scored at the end of the first half, scooping a glorious chance over the bar. The frustration there will be that the scoring momentum he built in the first two matches of the season has now been interrupted twice.

When Madueke did come on, he also missed a major chance — a gilt-edged one-on-one opening. It perhaps underlined that lingering lack of real ruthlessness, the very quality Viktor Gyokeres was meant to provide but simply has not. That is why Arsenal need to keep Odegaard and Kai Havertz fresh.

Rice, who always wants to play, did so here partly because Bruno Guimaraes’ ankle injury is still ongoing.

Even so, it still felt slightly unnecessary that he was driving himself on until the very end at right-back. At least Jurrien Timber is expected to return this weekend.

Declan Rice never eased off, right until the final whistle.

Arsenal’s defensive structure remained the more solid part of their display, though. Ezri Konsa has settled in so well, and inevitably looked far more assured than he did for England. He faced another major examination in this game and stood up strongly to Napoli’s attackers.

This was not a Napoli side in good form, though, and the absence of Scott McTominay only further highlighted their lack of penetration. The wider reality of the evening was also reflected by the number of empty seats. This was not the Stadio Diego Armando Maradona at its most volcanic, to borrow the description so often repeated because of the shadow of Vesuvius. It felt comparatively subdued.

Locally, it is said that this is because of what the Champions League opening round has become, a feeling made stronger when the team is out of form. Napoli’s supporters are not feeling especially positive right now after three defeats in a row — something that never happened during Antonio Conte’s tenure. Is the pressure already beginning to build on Max Allegri?

Arsenal’s 100 per cent record rolls on, though. Odegaard’s scoring run goes on as well. He is clearly feeling very good about himself right now. That self-belief has been missing, and it may be what finally completes this team.