As soon as the December draw for the Champions League round-of-16 threw out Real Madrid and Paris Saint-Germain, all eyes were on a certain French striker.
And for a long time Kylian Mbappe looked set to be the difference-maker between two European giants who are also in a tug-of-war for the forward's future.
His excellent goal in the first leg at the Parc des Princes was decisive then, and he terrorised Los Blancos further in Madrid.
But almost out of nowhere the tie was turned on its head, with Karim Benzema once again proving his master status with a truly exceptional display of ruthlessness as Madrid won 3-1 at the Santiago Bernabeu to secure their passage to the quarter-finals 3-2 on aggregate.
This was anything but predictable. After all, the tie was all set up perfectly for 'The Narrative' to settle things in this clash of titans.
For months, maybe years, Madrid have flirted with the idea of bringing Mbappe to the Spanish capital, even going as far as submitting huge bids for him last August.
Carlo Ancelotti is asked about him at pretty much every pre-match news conference, such is the obsession in the Spanish press, but PSG's resolve in August seemed to be paying dividends just over six months later, with Mbappe crucial last time and in the mood here.
Ahead of the trip to Madrid, PSG communicated how the Frenchman was a doubt due to a training knock. Whether that was the truth or subterfuge can only be confirmed by Mauricio Pochettino, but one thing's for certain, Mbappe looked as sharp as ever.
The warning signs were there – twice – inside the first 13 minutes. On both occasions, Mbappe managed to get in behind Madrid's riskily high defence, but he let the hosts off the hook each time.
Despite worrying signs for Madrid, at no point did you expect a tactical change from Ancelotti given Madrid's desperate need to get at least one goal.
As such, the Mbappe 'cheatcode' was seemingly always going to be a possibility for PSG as long as the other 10 remained focused. For all the obsession over tactics, Pochettino's approach seemed to resemble that of millions of FIFA video game players from down the years: kick the ball beyond the defence for the really, really fast chap.
And that was exactly how the breakthrough came. PSG defended a corner and Neymar picked up possession deep inside his own half. Mbappe was already on the charge and the Brazilian clipped a first-time ball over Dani Carvajal.
Mbappe surged forward, shaped to curl his shot around Eder Militao and then picked out the near corner instead, usurping Zlatan Ibrahimovic as PSG's all-time leading scorer in the process.
The offside flag then cruelly, but crucially correctly, denied Mbappe what would have gone down as a classic Champions League goal early in the second, latching on to a throughball and beating Thibaut Courtois with an exquisite stepover before he'd even touched the ball and slotting into an empty net.
And almost instantly PSG's performance went stunningly awry.
Gianluigi Donnarumma's dawdling on the ball gifted Madrid an equaliser as Benzema charged down his clearance and then stabbed in from Vinicius Junior's cut-back.
Suddenly Madrid were like a pack of rabid wolves. Donnarumma's hesitancy and indecision began to overcome the rest of his back four, with PSG almost in a flash going from in control to utterly terrified.
Just 15 minutes later, 1-1 turned into 2-1, with Luka Modric doing brilliantly in midfield to pick out Vinicius, who had the presence of mind to patiently wait for the Croatian to appear on the edge of the box, and he slotted the ball through to Benzema to steer home.
Then, within seconds of PSG restarting the game, Marquinhos panicked in his own area, flicking the ball into the path of Benzema who unleashed an impossibly cool finish into the bottom-right corner, picking it out with the outside of his foot without breaking stride.
It sparked bedlam in the stands of the Santiago Bernabeu as it quickly dawned on the Madrid faithful and players that the tie was theirs. While PSG had the best part of 15 minutes to fight back, their mystifying lack of composure since the hour mark had already sapped them of belief.
Mbappe looked on, having gone from unstoppable to helpless in the space of just a few second-half minutes.
Of course, a key difference between the goalscorers was their respective supporting casts. While Lionel Messi, Marco Verratti and Neymar looked impressive in the first half, they were nowhere to be seen after half-time.
Madrid, on the other hand, had already looked a threat with Vinicius up top alongside Benzema. The Brazilian excelled where his compatriot Neymar could not – the young winger was relentless, working exceptionally hard throughout to ensure Benzema didn't have to do it alone, even if the headlines will suggest it was all him.
There is a school of thought that this tie will ultimately determine where Mbappe ends up next season. On the evidence of this, a front three of him, Benzema and Vinicius will be mouthwatering.
Mbappe has so far been very calm and unequivocal when asked about his future, but Madrid have given him a glimpse of what awaits.