A first-half goal from the truly awesome Victor Wanyama and a second from the precocious Tony Watt eight minutes from time gave Celtic a historic win over Barcelona.
The finest football team on the planet were taken down by group of players who combined to create a passion and purpose which could not be denied.
The collective will devoured the individual skill, and Neil Lennon's side now have the respect of the football world. They also have seven points from four games in Group G, and a serious chance of qualifying for the last 16.
And, on the night Barack Obama headed back to the White House, the green and white house was in danger of having its roof removed.
The celebrations will still be continuing when Lennon takes his side to Lisbon in a fortnight, seeking the result that would carry them into the knock-out stages.
Wanyama's header from a Charlie Mulgrew corner after 21 minutes set them on their way to an epic victory.
When substitute Watt – at 18, only two years younger than the Kenyan – kept his cool to capitalise on a Xavi mistake late in the game, all the pains from the blocks, tackles, and runs disappeared.
Not even an injury-time goal from Lionel Messi could spoil the moment or dent the dream.
Celtic had beaten Barca 2-1, and the fans just could not get enough as they cheered their warriors from the field and celebrated the club's 125th birthday in style.
They had done it. They had beaten the odds, and beaten Barcelona. No praise can be too high, because this was done the hard way.
The absence of skipper Scott Brown – well disguised by the midfielder during all his pre-match media work – was partially cancelled out by the presence of Georgios Samaras, who had recovered from the ankle injury which forced him off in the Nou Camp a fortnight ago.
Lennon still considers that was the moment the Hoops' chances of pulling off an upset disappeared, so important is the Greek international and last night's captain, to his side's potency in Europe.
The manager has also invested great faith in Venezuelan loan singing, Miku, and this meant that rising star, Watt, had to settle for a place on the bench, along with less-known teenagers, Marcus Fraser and John Herron.
That was a further reminder of the number of important players out of action, among them James Forrest and Gary Hooper.
However, on the Barca bench lurked danger in the form of David Villa, Cesc Fabregas, Martin Montoya and Gerard Pique.
But no game has ever been won on reputation alone, and collective spirit can be an effective antidote to stardust.
Lennon had warned that his men would have been dogged and disciplined, brave and belligerent – and that was just to get a touch of the ball.
Barcelona have the awesome ability to retain possession for long periods, even against the likes of Chelsea and Real Madrid.
The secret is not to get desperate and lunge in, but to stay upright and hold your position.
Wanyama showed the way with a performance which confirmed he does not look out place when mixing it with the likes of Xavi, Andres Iniesta and Messi.
His goal was the icing on the cake, and if Lennon valued him in at £25million before this game, that might not seem quite so fanciful now.
However, it takes much more than one man playing at that level to allow a team to compete with Barca, and the call from the Hoops boss for everyone to rise to the occasion was answered in spades.
Even when Tito Vilanova's men played keep ball for around 20 minutes after Celtic took the lead – lifting their possession in the first half to 79% – there was a composure and assurance about Celtic's defending which underlined how they have developed as a unit in a short period of time.
Sure, they rode their luck at times, no more so than when Messi smacked a shot off the cross bar and when Alexis Sanchez saw a shot beat Fraser Forster but hit a post and run wide.
But getting to half-time ahead – which they just failed to do in the Nou Camp a fortnight ago – was a major achievement and staging post for the Parkhead club.
Where the woodwork had denied Barca in the first half, Forster did it in the second, the giant keeper reserving his best for a double stop from Alexis and then an even better flying save from Messi as the screw was turned.
The departure of Mikael Lustig with a hip injury might have upset things, but the fact Watt came on in his place meant there was at least now an outball due to his pace.
And with Beram Kayal on to replace Samaras, Lennon's call to see the job through didn't go unanswered.
Prepare for a DVD of the night the Hoops beat Barca to be rushed out. It will be a Christmas best seller.