Pep Guardiola dethroned the “kings of the competition” — now his Manchester City side can claim the crown for themselves.
Beating Real Madrid was the big win and the big performance in Europe that he has craved since taking over at the Etihad Stadium four years ago.
Now, his side can have no nerves about taking on the rest of Europe.
City were quicker, sharper, more intelligent and more threatening than a Madrid that had incredibly never tasted elimination in the Champions League before in Zinedine Zidane’s four campaigns as a manager.
But Guardiola’s side were also nervier and more wasteful as they faced the threat that another European challenge could end prematurely.
City and their coach have had five months to think about nothing else but the Champions League with their Premier League title challenge conceded long before football was shut down by the Covid-19 outbreak.
Leading 2-1 from their first-leg victory at the Santiago Bernabeu, a place in the quarter-finals looked a formality had the second leg been played in March as scheduled.
But that win was 162 days ago and a lot has happened in the meantime — not least Zidane rebuilding his side’s confidence and securing a first La Liga title in three years.
Guardiola, though, was brave as ever.
Even with a slender lead he took the game to their opponents. He has often been accused of over-thinking big matches and he again went for an unorthodox line-up but he overran Madrid’s ageing midfield and hassled their nervous backline all night.
Academy youngster Phil Foden started the biggest game of his career as a false nine, striker Gabriel Jesus played as a left winger, where he had troubled Madrid throughout in the Spanish capital and, with Benjamin Mendy suspended, Guardiola moved Joao Cancelo to left-back.
It worked perfectly in the opening exchanges with Madrid, missing the influence of their banned captain Sergio Ramos, looking tentative playing out from the back with the pressure of City’s hard-working front three.
Jesus hassled Raphael Varane into a clumsy mistake and rolled the ball into Raheem Sterling to tap home for the perfect start.
It should have settled nerves but missed chances only seem to ramp up the pressure on the home side.
Guardiola, himself, patrolled his technical box like a caged tiger, as Foden and Sterling missed chances to press home their advantage.
And when Cancelo’s weak challenge allowed Rodrygo to fire in a 28th-minute cross that Karim Benzema headed home emphatically, it was game on.
Question marks over the rigidity of their own backline have persisted all season, and with Fernandinho recalled after the bombshell Eric Garcia announcement that he wants to leave on the eve of the game, they could have easily buckled.
But still, City pushed forward and dominated possession. Sterling and Ilkay Gundogan missed chances until Jesus forced Varane into another clumsy mistake and when he squeezed in a second, there was no coming back.
By the final whistle, City were pulling the visitors all over the pitch with Kevin De Bruyne and Rodri strangling the midfield.
It’s the confidence boost that they've so badly needed and Guardiola may never have had a better chance to win the trophy during his time at the club. After the game, he seemed to understand the significance of the result.
"Of course it’s important," Guardiola said. "For Real Madrid and Barcelona to be in the last-16 is normal, you have to beat them to win the Champions League. Barca, Bayern, of course it’s important for this and the future.
"We beat Barcelona here and it’s quite similar. We’ve only done the last decade, not just for the players for the club, for the workers, for our fans."
Next stop is the mini-tournament in Lisbon and City have shown they are more than capable of winning single knockout games, having won four of the last six domestic cup competitions on offer.
But after beating the record holders, City can now take on the best in Europe without any fear.