Pep Guardiola once headed to the Etihad with Bayern Munich and plotted Manchester City's downfall - now it is very much roles reversed.
The Catalan, almost 10 years ago, observed as his team played perfectly in his image, dominating proceedings on the pitch. They would leave their opponents chasing shadows as his possession-based system led to one of the finest displays of his managerial career.
City were on the receiving end as Bayern, who'd then only been coached by Guardiola for a matter of months, proved that their manager's methods were universal amid doubters who felt he benefitted excessively from the likes of Lionel Messi, Xavi and co during his Barcelona tenure.
The headline stat from Bayern's 3-1 win at the Etihad in 2013 was a second-half period in which they made 94 consecutive passes across three minutes and 27 seconds. Toni Kroos made 18 of those passes, Bastian Schweinsteiger 13, Franck Ribery 12 and Arjen Robben 14. City had no answers.
That passage of play came at a time when the Bavarians were already three goals to the good. It was the definition of controlling a game.
City were unable to come back at their opponents as they simply couldn't get hold of the ball. There was talk of Bayern being his all-conquering Barcelona's second coming, that another of European football's aristocracies was submitting to a vision built at La Masia.
Dutch star Robben though dismissed links with the great Catalan side. Happy with the comparison he was not.
He said: "We have produced 80 fantastic minutes but we aren't Barcelona MkII. I understand the comparisons but we don't have players like Xavi or Messi and we are, basically, different. We just want to dominate games by dominating possession."
Senior figures at the club were purring. Then-Bayern president, Uli Hoeness, claimed: "For 80 minutes we played perfect football – the best football I've seen in my life."
Superlatives continued back in Bavaria following the display in October 2013 - and they would continue through Guardiola's tenure as the Bundesliga and the Champions League were the stages upon which his German orchestra to churned out symphony after symphony.
The failure however, was the inability to turn that into a European Cup triumph - a trophy Die Roten had won in the month prior to Guardiola's arrival, beating Jurgen Klopp's Borussia Dortmund at Wembley under Jupp Heynckes.
And so to the present day - where that trophy still eludes Guardiola.
He's often reminded of it and accepts - rather haughtily - that some will view his time in Manchester as a failure if he doesn't win it with City, at a time when English football has very much got used to the colour sky blue. They've dominated domestically and come close in Europe, but not close enough. Their false 9 system led to a final and a semi-final in successive years, but they were undone by Chelsea and Real Madrid respectively.
The Manchester outfit are now purring with a recognised No 9. They've put in two of their best performances of the season in successive weeks against Liverpool and Southampton - winning 4-1 on both occasions. Julian Alvarez and Erling Haaland have led the line as City and Guardiola have adapted their style.
It is in the Champions League that their lack of a striker has cost them most, but they'll be hoping against Bayern their impressive form continues. In his Bundesliga days Haaland scored five times against the Bavarians and will look to add to that total on Tuesday night.
Guardiola will have to overcome Thomas Tuchel, who recently took charge at the Allianz Arena. The former Chelsea tactician has thwarted the City boss previously and he's under no illusions of what he'll face.
The Catalan said: “He’s so creative with good build-up and connection, good runners and players who are good in the spaces. We see with Tuchel, maybe they will do something new tomorrow. We will try to figure out the quality they have in all departments."
Bayern themselves, who saw off Freiburg at the weekend, know they face among the toughest tasks in world football. Matthijs De Ligt said: “Out of all the teams [we have faced], Manchester City is the strongest because over the last five years they have won the Premier League four times."
Guardiola would no doubt take a repeat of his dominance 10 years ago, simply swapping reds shirts for blue ones. He's never faced Bayern since leaving in 2016 but has played down the impact of his defeats, citing the records of sporting greats who endured losses more than victory.
"Michael Jordan, the best athlete for me in basketball, won six NBA titles out of 15 years. He loses more than he wins," said the City boss.
The Chicago Bulls legend is widely considered the best basketball player of all-time. Champions League success for Guardiola, alongside a possible treble, could well see him hailed with the same title.
