Saturday's fixture between River Plate and Boca Juniors was going to be the biggest club match in the 127-year history of Argentine football.
It was the biggest club match of 2018 in the world and, after a 2-2 draw in the first leg, was tantalisingly poised.
For once, the Copa Libertadores final was getting worldwide attention from fans salivating at the prospect of two of the bitterest rivals in world football taking each other on for the right to own South America again.
Whichever way you looked at it, the occasion could not fail to deliver excitement, drama and a story that would be talked about for years.
Two hours before what should have been the kick-off, the Black Eyed Peas boomed out of the speakers in River's Estadio Monumental, telling us that it was going to be a good, good night.
It turned out to be anything but.
All week, fans from both sides had talked about their sleep depravation and fear of losing, which seemed greater than the thought of winning.
Demand for tickets was predictably high, as was the opportunity that the market provided.
One man exchanged his ticket for a job, while there were reports of others being sold for six-figure sums.
The president of River Plate, Rodolfo D'Onofrio, was forced to change his WhatsApp profile picture to one that simply said: "I have no tickets".
"This is an honour and a huge responsibility to organise this event," he told me. "For us River fans it's very significant because we'll show the world the passion of Argentina and how we feel about football."
On the day of the match, the mood seemed to have shifted from anxiety to excitement.
En route to the stadium, through the evocative crackle of an AM radio, a presenter declared it to be "the match of all time".
Security was stringent with regular checkpoints halting early arrivals in their tracks at regular intervals.
But, as we took our seats in the famous stadium, chattering excitedly about what was to come, news filtered through of the attack on the Boca Juniors bus.
It was illustrated with video and photos on social media. But much of what followed for the rest of the weekend was richly marinated in rumours and conspiracy theories.
First, there were reports the Boca players had been attacked with pepper spray by River fans in a copycat act of reprisal for what Boca fans did to the River players in 2015 when they last met in the Libertadores.
Then, as it became clear that the players had inhaled teargas fired by police, there was news that flying glass had gone into the eye of the Boca captain Pablo Perez. Other outlets said he just had a cut arm.
Inside the stadium, an atmosphere was building. But you knew the best of the fans' passion and noise was being kept in reserve for the match itself.
A hissing cascade of red and white plastic streamers was released from the top tier in preparation to welcome players who would never set foot on the pitch.
Then, where are the team sheets? And why has the booming music been switched off, albeit mercifully?
Social media posts began talking of a possible delay to kick-off.
The singing declined and became desultory conversation as the energy was palpably sucked out of the air. An atmosphere that had been so vibrant and full of promise now lay heavy on the stadium.
Someone tweeted that Boca had demanded the match be awarded to them, as it had been awarded to River after the pepper spray incident of 2015.
But someone else said that the Fifa president, Gianni Infantino, had threatened to disqualify Boca if they didn't play.
The trouble was that all of these contradictory rumours were coming from people who were supposed to be in the know – local journalists and big media organisations. But what was fact, and what was fiction?
The kick-off time of 5pm local time came and went, just as we heard that Perez had gone to hospital to get treatment for his eye.
But as we were waiting to hear about his condition, news came through that the match would be delayed by just an hour.
The music returned but not the crowd's earlier carefree mood.
And they were right. No sign of any players by six o'clock. But just as talk was growing of an actual postponement, Boca coaches came onto the pitch to put out cones and balls for a warm-up, and they were followed by the referee and his assistants, to great cheers from the fans.
But a restless feeling that the game really wasn't going to be played continued to gnaw.
Older hands in the press box spoke of how the 2015 abandonment had never been communicated to fans for fear of antagonising them. Instead, the authorities had relied on fatigue among the spectators to blunt their inevitable anger and disappointment.
But once again, gloomy speculation was balanced by promising news.
The official Boca Juniors Twitter account had announced a starting line-up and, amazingly, Perez was in it.
But where were the actual players?
On their way back to their hotels, it emerged. The game really was not going to happen, but no-one told the crowd that.
But, thanks to social media, the news got around, and they began to trudge out of the stadium as the conspiracy theories started to take hold.
One said the attack on the bus was an act of revenge by the River Plate Barra Brava – the powerful and violent wing of its hardcore support – after its leader's home had been raided by police a day earlier.
Another said the police let it happen to undermine the governing authority of Buenos Aires.
Meanwhile, what was going to happen to the biggest club match in Argentine football history?
Boca demanded a walkover, said some. It was going to be switched to another stadium, said others. It would be played behind closed doors, was a report that was gaining momentum.
What was for sure, was that it was a night of humiliation for Argentine and South American football.
Alejandro Dominguez, the head of South American football, launched a flurry of midnight tweets describing events as a disgrace and not pulling any punches in blaming the organising authorities.
But he did hope that Sunday would pass peacefully, which suggested a mere 24-hour delay before the match was played in front of a full Monumental.
And he reinforced that impression on Sunday morning on local TV, when he reiterated the game would kick off at 5pm, with fans in attendance.
So the fans went, but in duty rather than jubilant expectation. They went out of blind loyalty, to support their team but, as one said to me, they were sad.
"Even if we win, in the next months, everyone will remember this for what happened yesterday," he said. "This game shouldn't be played today."
Then, a rare piece of concrete news. Boca Juniors released a statement confirming that they didn't want to play because conditions for the players weren't equal.
Then, just 10 minutes later, an uncharacteristically swift and unequivocal development – Conmebol president Dominguez confirmed the match was off.
And that was that.
Beneath glorious sunshine, once again the River Plate fans trudged away. But there was no anger, there was no emotion at all.
The shame of the weekend had broken them.
A match that would carve the names of a few lucky players into the history of Argentine – and world – football did not take place.
Instead, this crazy weekend will be remembered forever as one of Argentine shame, laid bare before the astonished gaze of the world.