The waiting was the worst bit. During those long hours before the game, a barren desert of time, the Liverpool fans paced the Anfield concourses, hovered in the gangways, as if trying to find something to do. But there was nothing to be done, not yet.

Then, at kick-off, Manchester City made them wait some more. They won the toss and ordered Liverpool to swap ends with them, so they wouldn’t be playing towards the Kop in the second half. It seemed barely significant at the time. But as they trooped off the turf defeated and disgusted, their European adventure hanging by threads, it felt tempting to anoint it as the pivotal moment of the game. For it was a decisive acknowledgement by the visitors of Anfield’s power to stun and stir, to gird bodies and mess with heads.

The next half hour, it has to be said, passed in something of a blur. For City, for Liverpool, and probably for most of the people in the stadium, Liverpool’s astonishing opening burst will be one recalled not in moving images but a series of devastating stills. A steward giving a thumbs-up and a beaming smile to his mate in the next section as Mo Salah put a delirious Liverpool 1-0 up. The split-second just after Alex Oxlade-Chamberlain struck the ball from just outside the area, when for a moment it seemed like the stadium had fallen completely silent, not in anticipation but in puzzlement, for the ball had simply disappeared: only to reappear, 25 yards away, as a bulge in Ederson’s net.

Liverpool vs Manchester City - player ratings Show all 22 1 / 22 Liverpool vs Manchester City - player ratings Liverpool vs Manchester City - player ratings Karius – 6 Never tested. City didn’t have a single shot on target. Seriously. Liverpool vs Manchester City - player ratings Alexander-Arnold – 8 Coped superbly with the threat posed by the lively Leroy Sane. Liverpool vs Manchester City - player ratings Lovren – 7 Actually looks a decent defender with Van Dijk beside him. The Croat produced a crucial interception in the second half to deny David Silva a free shot at goal from Sane’s cut-back. Liverpool vs Manchester City - player ratings Van Dijk – 7 A Rolls Royce of a defender. He’s been the answer to Liverpool’s defensive troubles since arriving in January. Liverpool vs Manchester City - player ratings Robertson – 8 Full of energy all game. The Scot suits Jurgen Klopp’s style of play down to the ground. Liverpool vs Manchester City - player ratings Oxlade-Chamberlain – 8 Scored the second-best Champions League goal of the week as his 25-yard drive rocketed past Ederson to make it 2-0. Liverpool vs Manchester City - player ratings Henderson – 7 Solid in midfield but booked late on for a foolish challenge and will now miss next week’s second leg. Liverpool vs Manchester City - player ratings Milner – 8 Colossal in the first half and showed good aggression to win the ball back for the hosts in the build-up to their second goal. Liverpool vs Manchester City - player ratings Salah – 8 Scored and assisted on another memorable Anfield outing for the Egpytian. Injury forced him off early in the second half, though. Liverpool vs Manchester City - player ratings Firmino – 8 His tireless running brought about Liverpool’s opener as he dispossessed Kyle Walker to give Salah an easy finish. Liverpool vs Manchester City - player ratings Mane – 8 Headed home from Salah’s pinpoint cross to make it 3-0. Liverpool vs Manchester City - player ratings Ederson – 5 Got a hand to Mo Salah’s opener for Liverpool but couldn’t keep it out and stood no chance with the Reds’ second and third goals. Liverpool vs Manchester City - player ratings Walker – 5 Cost City the opening goal of the game as he dithered on the ball inside his own area. Liverpool vs Manchester City - player ratings Otamendi – 5 Booked for a rash challenge on FIrmino in first-half injury time and never looked comfortable. Liverpool vs Manchester City - player ratings Kompany – 6 Might’ve blocked Salah’s opener on the line if it wasn’t for a touch by Ederson. Liverpool vs Manchester City - player ratings Laporte – 5 Played well at left-back at Selhurst Park on Saturday but failed miserably in his attempts to contain Mo Salah tonight. Liverpool vs Manchester City - player ratings De Bruyne – 5 Chose a bad night to produce perhaps his worst display of an otherwise-superb season. Liverpool vs Manchester City - player ratings Fernandinho – 5 Not his usual self at the base of midfield. Liverpool vs Manchester City - player ratings Gundogan – 5 Pep Guardiola’s decision to start with the German ahead of Raheem Sterling backfired and he was substituted after an hour. Liverpool vs Manchester City - player ratings Silva – 6 Failed to really exert any influence on the match, which is unusual for a player who is so frequently the most influential player on the pitch. Liverpool vs Manchester City - player ratings Sane – 7 City’s liveliest player in the first half but couldn’t do it all on his own. Liverpool vs Manchester City - player ratings Jesus – 5 Anonymous on a night when the Blues might’ve benefited from having the more experienced but currently injured Sergio Aguero up front.

Or the ball hanging in the air as City’s defenders stared at it like a dying sun, Sadio Mane advancing on it like the only man in the stadium who knew what was about to happen. Or the mass of red shirts by the corner flag as Liverpool celebrated again, and again, and again, City bickering amongst themselves in the centre circle with all the puny rage of fisherman arguing how best to push back the sea. Or Trent Alexander-Arnold taking Leroy Sane’s lunch money and surging up the right wing. Above all, it felt weird. It felt like watching somebody else’s scripted movie. It felt almost unearthly.

Jürgen Klopp is a man of faith, in more senses than one, and somehow he manages to produce more of these moments than anyone else. Look, I can see your arched brow at this point. I sense your starchy cynicism. I’m aware, even on the most elementary level, that football can’t simply be boiled down into a thick soup of emotion and belief and desire. I get that, I really do.

But equally, you can show me all the chalkboards and heatmaps on the internet, spit all your key performance metrics in my direction, blurt as many random Spanish words at me as you want, and you won’t get remotely close to explaining, to your satisfaction or mine, how Scotland’s Andy Robertson - a player who this time last season was getting very slowly relegated with Hull - can ski through the entire City team like the illegitimate offspring of Rivelino and Hermann Maier. You can’t tune into the unique footballing frequency that makes the best team in England (Europe?) look like amateurs without really seeming to do very much wrong at all. But that’s the very definition of faith: the substance of things hoped for, in the evidence of things not seen.

In any case, it doesn’t really matter whether or not you think Liverpool’s first-half blitz was the result of their collective possession by some sort of supernatural orenda, or Nicolas Otamendi just being a bit flat-footed. Your belief isn’t the issue here. The point is that Liverpool believed, unflinchingly, unquestionably and with the zeal of the self-appointed chosen. “We have to change from doubters to believers,” Klopp announced when he first arrived at Anfield 30 short months ago, and in a sense those few words have encapsulated his reign to date: the inextinguishable idea that in the face of scepticism, economics, common sense and most of the available evidence, salvation is close at hand.

And yet as faith shakes, so can faith be shaken. The injury to Mo Salah deprived Liverpool of their holy trinity: their main goal threat, their leading creator and their most effective ball-winner. The introduction of Raheem Sterling as a second-half substitute brought out Anfield’s surly, petty, covetous side. The high press began to sag. At one point, James Milner gathered the ball on the edge of his own area and simply booted it as far away from him as possible. Rarely has a team 3-0 up looked so convinced of impending disaster.

How can Scotland’s Andy Robertson ski through the entire City team like the illegitimate offspring of Rivelino and Hermann Maier (Reuters)

Liverpool had returned to the earthly plane, and from here the view was far bleaker. Even as the referee’s whistle called time on act one of this quarter-final, over the next six days the clouds of doubt will rain what-ifs upon this Liverpool side and its adherents. What if Salah doesn’t recover in time? What if City nick an early goal at the Etihad next Tuesday? What if, somehow, Liverpool forget to forget: what if they remember their human fragilities and fallibilities and shed the cloak of invincibility that they wore here so proudly for half an hour?