Unbelievable. People just stood and stared at the vacated pitch and through their awe kept muttering unbelievable. It was over an hour after the final whistle. Serious football individuals, men who had been watching the game for decades were saying it. The managers were saying it. The players were saying it. It was unbelievable how many people were saying it was unbelievable.
For once the most overused adjective in football did not seem unwarranted. There had indeed been times when the captivating events in the Westfalenstadion on Wednesday night had defied belief. When football reporters are continuously asking `what's the score now?', you know that the match is unfolding in the most unexpected fashion.
In Dortmund their queries were all the more understandable. Liverpool versus Alaves was meant to be the meeting of two sides of caution. Everyone said it would be tight. Nobody said it would be unbelievable.
Alaves, after all, had the best defence in Spain last season, while Liverpool had been pilloried for their defence-first attitude in Barcelona and Cardiff. Cagey, that's what people said it would be.
Cagey? It turned out that the cages had been flung open. The forwards had taken over the asylum. Goals reigned and they rained. From Markus Babbel's fourth minute opener to Delfi Geli's golden own goal 113 minutes later there was a torrent of attacking and a fantastic absence of caginess. Both sides' defenders proved defenceless.
Dan Eggen, a Norwegian international, was withdrawn after 23 minutes by Alaves. Stephane Henchoz, another international and one of Liverpool's players of the season, suffered the same fate half an hour later because, in Gerard Houllier's words, Henchoz was "sinking". It was that kind of night at the back.
Maybe even Liverpool's defenders were unnerved by the ease with which those in front of them opened Alaves up in those first 16 minutes. Then, Markus Babbel and Steven Gerrard had given Liverpool a two-goal lead and altered the whole complexion of the evening. The supposedly cagey demeanours disappeared. The subsidence was spectacular entertainment.
It feels slightly revisionist and churlish therefore to raise a couple of quibbles almost 24 hours later. But they feel legitimate even if untimely. First, seven of the nine goals could be dissected Alan Hansen-style for the "shocking" defending or the ineptitude of the goalkeeping; particularly Alaves' Martin Herrera for giving away the penalty and Geli's decider, and Sander Westerveld for Jordi Cruyff's 89th-minute equaliser.
Second, once it was all over and the contestants started talking animatedly about what they had just experienced, Houllier used a couple of phrases that require scrutiny even if the Liverpool manager deserves leeway for understandable excitability.
"Immortal," as in what his players had become, was one Houllier remark; while "beginning" of a new era or "dawning" of a new era and other variations need to be put in perspective. Yes, Liverpool have advanced significantly since Christmas and Gary McAllister's role in the past two months has been nothing short of remarkable. And yes, they have completed a great cup treble.
But, thinking back to last year's UEFA Cup final in Copenhagen between Galatasaray and Arsenal, it is difficult not to think that that fine, close match was technically superior to what was witnessed in Dortmund. Moreover, although Liverpool may qualify for the third Champions League place at Charlton Athletic tomorrow afternoon, the memory of Leeds United's comprehensive victory at Anfield a month ago is fresh enough for it to be argued that David O'Leary's side is better than Houllier's. Arsene Wenger's certainly is, despite the scoreline in Cardiff.
Houllier, though, has won plenty of room for minor exaggerations to be accommodated. A major part of his task at Anfield was to tackle the slacker culture that had developed under Roy Evans. That is harder and more controversial than many may think - remember Alex Ferguson's difficulties with Norman Whiteside and Paul McGrath. Houllier's problems with Robbie Fowler, for example, are not insignificant. Fowler is a Scouse emblem. As such he has emotional power.
How Houllier handles Fowler after tomorrow will be intriguing. Fowler's stock as a striker has fallen even bearing in mind his goal in Dortmund. It would represent bad business if they turned down £10£15 million for Fowler when they think they can replace him with, possibly, David Trezeguet for less.
Trezeguet has endured a frustrating year with Juventus and has been approached by Liverpool - Houllier coached Trezeguet as a French under-18 and under-19 - but is said to prefer a move to Spain.
But the fact that Houllier is looking at that level of player is encouraging for all Liverpool supporters. It suggests that when all the euphoria dies down Houllier will be back making realistic assessments of where his team are.
That has been his greatest strength as Liverpool's sole manager. He has not shirked and he has been prepared to look ugly. Wednesday night may well come to be seen as a beautiful hysterical interlude in an otherwise steady progression. Dortmund will never be forgotten, but the latter is much easier to believe in.