Thus far unable to catch Pep Guardiola’s latest creation in the league, Liverpool took an almighty revenge on one he made earlier, and the history of this great club in European football may never be the same again.

They thought they had written the book on the matter of comebacks in the Champions League – concerning that story you may have heard from 14 years earlier in Istanbul, although this one, it has to be said, bears comparison. Three goals down to the Barcelona of late-era Lionel Messi, his genius declared in no uncertain terms in the first leg, and yet by 10pm the world’s greatest player was heading back down the tunnel defeated, a man with a wild look in his eye.

No team does this in the second leg of a Champions League semi-final without wondering if the hand of destiny is not ushering them down an alternative path to glory to the one they have chased all season. On Monday night, Manchester City edged the Premier League just a little further from Liverpool’s grasp which felt monumental - and then came Tuesday night when the response at Anfield was, quite frankly, stupendous.

How did this happen? Klopp reflected later, “I said to the boys before the game, ‘I don't think it's possible but because it's you we have a chance"'. But even that only went some way to explaining the impossible. How did they do it without Mohamed Salah, or Roberto Firmino or assorted others, plus Jordan Henderson on one leg for half the game, as well Andy Robertson carted off at half-time for an injury involving Luis Suarez? How did they do it against one of the best teams of this era or any other?

How did they do it with Divock Origi in attack? Ordinarily glad just to be a substitute on a night such as this, he was the two-goal match-winner. The best striker on the pitch on a night when he could not be sure that every opponent would know who he was without glancing at the back of his shirt. Robertson’s replacement, Georginio Wijnaldum, scored goals two and three in the second half and yet when the Scot went off at half-time it felt like just another blow that would make the task impossible.