THEY came early to create a memorable atmosphere but, by the end, large swathes of Celtic fans couldn't wait to get home. It was too painful.
The frustration this morning for Neil Lennon will stem from the realisation that it could have been so different, for reasons that extend beyond the lenient approach which the Spanish officials took towards the Juventus method of defending corners.
The game wasn't decided there.
Lennon's charges produced a 45-minute display which would have caused any opponent difficulty, a power-packed effort which matched the epic performance against Barcelona in November. But they had already gifted their opponents a head start and eventually ran out of steam, short of the guile to retrieve the situation.
It is the first clause in that sentence which will trouble Lennon after his pre-match gamble backfired in spectacular circumstances.
The Armagh man had spoken beforehand about springing a surprise in his team selection and the decision to opt for Efe Ambrose just 48 hours after his winning involvement in the Africa Cup of Nations final in Johannesburg ticked that box.
The 41-year-old acknowledged that it was a risk to use a player who effectively had no preparation after a 12-hour flight. Sadly, the Nigerian emerged with the look of a man suffering from jetlag and, within three minutes, he was central to a horrific defensive episode. Facing his own goal chasing an Italian punt, Ambrose came under pressure from the impressive Juve striker Alessandro Matri and was timidly pushed aside.
With goalkeeper Fraser Forster exposed, Matri clipped the ball towards the empty net with a flick that crossed the line before Kelvin Wilson could clear it. The linesman may not have realised that but Claudio Marchisio made absolute sure by crashing home the loose ball to save the match officials an awkward moment.
Now, Celtic had no option but to attack the Serie A leaders, although in the short period prior to Matri's strike their approach signalled intent.
After the phenomenal reception from the crowd that is customary on big European nights in these parts, the hosts burst out of the blocks with purpose and Victor Wanyama unleashed a shot that Gianluigi Buffon nervily fumbled behind for a corner.
The Kenyan, as ever, was a central part of the Celtic recovery strategy.
Lennon had protested beforehand that his team don't get enough credit. Yes, they produced an intensity here that is in keeping with the stereotype of a British team. But there was method to the application, and fluid movement between their front three in order to work the full-backs, Emilio Izaguirre and Mikael Lustig, into crossing positions.
What they missed in a relentless first half was the presence of Georgios Samaras to aim for. It was deemed too much of a risk to involve the hamstring victim. James Forrest was recalled to help Kris Commons in attempting to bridge the gap between midfield and attack. They did extremely well in general play, but struggled in terms of end product.
There was an abundance of chances, with Commons threatening on three occasions, notably when he was desperately unlucky with an inventive flick from a Lustig centre.
It came in a frenetic period where the natives had managed to unsettle Juve, with even Andrea Pirlo temporarily knocked out of his stride.
Juve boss Antonio Conte had noted the fact that 40pc of Celtic's Champions League goals had come from set-piece situations and Stephan Lichtsteiner was tasked with preventing Gary Hooper from standing in front of Buffon.
After a bout of wrestling, the pair were booked before the break.
Still, while the Juve rearguard that came into this fixture with a stingy reputation displayed the cynicism necessary to snuff away danger, they did not appear infallible and Wanyama could have done better when presented with a free header from a Commons corner.
The interval provided Conte with 15 precious minutes to regroup. His team's immediate response was impressive, as they stopped giving Celtic the freedom to build from deep, with the wing-backs in their 3-5-2 formation pressing earlier to reduce the deliberation period afforded to the home full-backs beforehand.
Suddenly, the Scottish champions elect were struggling to find space for the next 20 minutes.
They only created one opening during this period, but it was their best of the match. A short corner was diverted to Charlie Mulgrew, who flicked to the back post, where Ambrose had the freedom to atone for his earlier error.
Alas, the centre-half's header was devoid of conviction and Buffon collected.
As Celtic pushed, they flirted with danger, with the black shirts sensing the potential to kill this tie on the counter attack. Ambrose's partner Wilson was needed to make a smart block in a rapid move that culminated with a strike from Mirko Vucinic.
It was an portent for what was to come. With just over a quarter of an hour remaining, Lennon withdrew the tiring Commons and summoned young striker Tony Watt, the unlikely hero in the famous win over Barcelona. There would be no fairytale this time and, within four minutes, the Old Lady struck.
Again, the combination of Matri and Marchisio was crucial. The former, a clever attacker, dragged the Celtic centre-halves out of position with a run and first-time flick to release his counterpart. Marchisio showed his experience to finish clinically.
The prospect of a two-goal deficit heading into the second leg left Celtic with a task of mountainous proportions and before the optimists could make their case, Juve stepped up to make it Everest-like.
Ambrose, by now wishing he was on another plane, got himself into trouble, and two passes later, Vucinic slipped the ball under the body of Forster to remove the intrigue from a tie that promised so much.