Barcelona made history with an astonishing 6-2 win away to Real Madrid in May 2009.
In a season that saw the Blaugrana crowned treble winners in Pep Guardiola's first year as coach, their piece de resistance was undoubtedly their record-breaking result at the Bernabeu.
However, aside from humiliating their bitterest rivals, that legendary game in the Spanish capital also has the distinction of changing the landscape of modern football as we know it today.
Messi becomes a false nine
And we say that because Guardiola's ground-breaking decision to play Lionel Messi in the false nine position, which was thought to be extinct, arguably birthed the greatest period of success for any manager-player duo in history.
Besides, it paved the way for Messi to lead the line for Barcelona in a period that saw him win four consecutive Ballon d'Or trophies and set the world record for most goals scored in a calendar year.
So, yeah, it's fair to say that Guardiola's tactical call was an inspired one and you can hear the story of its inception from Messi himself in a 2020 interview with DAZN, per Goal. Take it away, Leo:
"I remember that it was a surprise for me, because I was called up the day before the game, was made to go to Guardiola’s office at the Ciutat Esportiva, and I was told that he had been watching Madrid’s games a lot, as he did with every opponent.
"He had been talking with Tito Vilanova and they had thought about me playing as a false nine. He was going to put Samuel and Thierry Henry on the outside, and I was going to play as the false centre forward.
"I wasn’t going to stay there, but rather come out and join up with the central midfield. The idea was that Madrid’s centre backs would follow me out, and the two fast wingers that we had would go around the back.
"In fact, one of Henry’s goals was like that. It was a surprise for us and for Madrid. I remember that we had a lot of possession, and we always had an extra man in the middle of the park.
"I’d never played as a centre forward, but I knew that position because it meant coming through from deep to get forward, without being a static number 9. It wasn’t a big change for me. I’d been playing on the outside for years, and so I knew what that position was about."
Messi's highlights vs Real Madrid
Pretty fascinating, right? But don't just take Messi's word for it because the footage of Guardiola's historic strategy has aged like a fine wine and continues to rack up massive views on YouTube.
In fact, those game-changing highlights from the Bernabeu have been played more than four million times since 2015 with YouTuber 'Αντωνης Τσικακης' perfectly illustrating the genius of the false nine.
So, do yourselves a favour, ladies and gentlemen, by watching a watershed moment in football history as Messi destroys Real with a tactic that would ultimately define the peak of his career.
Can somebody hang that up in the Louvre please?
A decision that changed football forever
Just like Messi said himself, you can see the way that Guardiola's unique positioning of him created space for Thierry Henry out wide, which ultimately kickstarted Barcelona's waterfall of goals.
Besides, it's easy to forget that Los Blancos actually took the lead on that fateful afternoon through Gonzalo Higuain, only for Guardiola's tactics to ultimately see their defence fall apart.
And although Messi 'only' found the net twice at the Bernabeu, the reverberations of his performance sent shockwaves through the sport that we're arguably still feeling to this very day.
I don't doubt for a second that Messi still would have gone on to produce superhuman statistics without this tweak, but Guardiola's inspired call gave him the final leg up to greatness nonetheless.