The other perception which Long’s goal changed was a much bigger one: that Ireland under Martin O’Neill simply did not have a result of this magnitude within their reach.

You sensed that Germany thought so too. For all their ownership of the ball in the first half, there was a conspicuous lack of urgency about their prolonged bouts of passing, as if they believed that, without having to break too much sweat, their innate superiority would sooner or later prevail against game but strictly limited opposition. Mesut Ozil’s relaxed smile after he spurned an inviting chance seemed emblematic of a Mercs and smirks mindset.

But then, let’s be honest here, you wouldn’t actually have found too many among a home support furiously whistling for a half-time reprieve, who would have been prepared to predict at that stage that things were going to get worse, not better, for the world champions – and positively euphoric for little old us.

In the first 45, Daryl Murphy might have been playing a more meaningful role as part of the first line of Irish defence rather than as a thorn in the side of Germany’s, but his prodigious work rate, allied to that of the likes of Walters, Hoolahan, Hendrick and Brady – and buttressed by a back four which belied its patched-up billing with a performance of huge discipline and bravery - meant that not only were Ireland still in the game at the break, they had a solid platform on which to build.

And build they did, with Martin O’Neill’s decision to deploy Long as an impact sub – however hateful that term must be to the man himself – entirely vindicated by the thrillingly decisive manner in which the Southampton man was able to exploit the opposition’s tiring legs and tiring minds with 20 minutes left on the clock.

In fact, the clock seemed to be on a tortuous go-slow for the remainder of the game, but the Irish players, though almost out on their feet after the huge mental and physical effort they’d put in, held firm to deliver a result to finally electrify the Aviva and establish a new high-water mark in Irish football history to replace that celebrated victory against Holland at the old Lansdowne Road in 2001.

And, frankly, it probably came as even more of a surprise to us than it did to a shell-shocked Joachim Low and his team of suddenly world-weary world-beaters.

You don’t have to look back too far to find the reasons why.

Leaving aside the facile games against Gibraltar, whose main function had been to garland Robbie Keane’s staggering goal record, Ireland had tended to do things, almost literally, by halves throughout this campaign, most notably in home draws with Poland and Scotland.

Late goals had also been a significant element in the team’s halting progress, Aiden McGeady setting the tone with his decisive moment of magic in the curtain-raiser in Tbilisi before Shane Long dealt another get out of jail card at the 11th hour at home to Poland.

Most celebrated of all, of course, was John O’Shea’s memorable intervention at the death in Gelsenkirchen to top off what was probably the most complete 90 minutes put in by Ireland in this campaign until, improbably and gloriously, they managed to go one better against the same opposition at the Aviva.

But where the team has been justifiably criticised for stuttering and unconvincing displays elsewhere in the group – the defeat in Glasgow being by some distance the most disappointing of the lot - they scarcely deserved some of the brickbats flung in their direction for their approach and performance away to the world champions last year.

At that early stage in qualifying, Germany might still have been finding their feet, and probably even their heads, after their hard-earned but deserved triumph in Brazil, but it always baffled me how anyone could ever have thought Ireland could afford to be adventurous against a side who, just a few months before, had humiliated the most famous football nation on earth and then kept the world’s greatest player under wraps, en route to lifting the sport’s most glittering prize.

In fact, Gelsenkirchen was as close to a textbook away performance as could have been desired of already weakened underdogs venturing into the lion’s den, Ireland holding a dominant home side at bay for a full 70 minutes and then, when the visitors’ resistance was finally broken, being strong-minded enough to muster the spirit, as well as those telling little touches of class – McGeady’s quick feet, Hendrick’s quickness of thought, O’Shea’s speed of movement - to strike back and salvage a point both precious and unlikely.

With the quality of the playing pool available to Martin O’Neill not significantly better than the one which he inherited from Giovanni Trapattoni – and inarguably inferior to the one the Italian had when Ireland narrowly missed out on qualification for South Africa 2010 – the joyous reception in some quarters to the ‘dream ticket’ arrival of the Derryman and Roy Keane always seemed based more on the management team’s intoxicating reputation than any sober recognition of the more prosaic reality of the talent with which they were going to have to work.

A more measured and reasonable demand of the new regime was that O’Neill’s renowned man-management skills would be sufficiently inspirational to extract more from less and get the team to punch above its weight, which is precisely what happened in Gelsenkirchen - and, even more upliftingly, happened again, and with even greater reward, in Dublin this week.

While the buck in international football, as in the club game, must always stop with the manager, there can still be no underplaying the limitations of the current squad, not least by direct and inevitably unflattering comparison with what was on offer when Irish football first arrived with a bang on the world stage. In making his team devilishly hard to beat and reducing even imperious opposition down to a level they found distinctly alien and uncomfortable, Jack Charlton’s rigid but aggressive game plan was a huge part of that longed-for success. And even those players who themselves initially found the manager’s approach not to their liking, were quick enough to come around when the brute philosophy of being effective rather than pretty produced a succession of crucial results.

Yet, when Kevin Moran, talking on the always excellent ‘Second Captains’ earlier this week, was asked if, as an Irish international, he ever went into a game in fear of big name opposition, his instinctive response was not to cite the reassuring presence of the World Cup-winner in the dug-out. Instead, he explained that the reason he never felt intimidated or inferior in the green shirt was because all he had to do was look around the dressing room to see a host of big players and big characters who’d already proven themselves at the biggest clubs of the day: Liverpool, Manchester United, Arsenal, Juventus, Celtic.

Of course, Moran was one of those titans himself, as was his old comrade Packie Bonner who, by coincidence, I bumped into on the streets of Dublin in the afternoon calm before the rapturous storm of Thursday night.

Packie hadn’t seen the interview but nodded in enthusiastic agreement as I relayed the gist of what Kevin had said.

And one of the heroes of Genoa made the further point that, excluded as Ireland’s current crop of players are from Europe’s premier club competition – compounded by a limited engagement with England’s top flight - the international game is effectively their sole exposure to football at the highest level, with the result that it’s both an education and an examination at one and the same time.

Well, on Thursday night, when least expected, emerging and developing players like Richard Keogh, Jeff Hendrick, Robbie Brady, Cyrus Christie and, most of all, James McCarthy, passed their toughest test yet – and with flying colours.

Yes, it was a performance rooted in the ancient Irish virtues – but it was a fresh and invigorating experience for this generation to be able to go beyond the acceptable concept of the moral victory to actually claim football’s biggest scalp. By having the guts and intelligence to see the 90 minutes through to a successful conclusion, they turned a familiar enough ball game into a whole new ball game.

As well as the ineffable joy which victory over the world champions brought , the result should act as a massive injection of self-belief for these Irish players as they now look to another tough test in Warsaw tomorrow night – but also, with increasing optimism, beyond.