Real Madrid may well be going into their second leg with Napoli thinking the tie is already over.
Zinedine Zidane's men won 3-1 at home against the Serie A side almost three weeks ago, so it goes without saying that they're the overwhelming favourites to qualify.
What they might not have contended with, however, is that this won't be a case of 11 v 11.
Los Blancos welcome Cristiano Ronaldo back after he missed the Eibar game, but even CR7 could struggle to match the passion and enthusiasm of the 60,000 Napoli supporters who'll be in attendance at the San Paolo stadium.
An educated guess would also predict that Zidane's men might not be feeling their best today.
That's because, as reported in Marca, around 100 Napoli fans gathered outside the Real Madrid team hotel with the sole aim of making as much noise as possible.
As you can see in the footage below, the group were intent on making themselves heard, but they also took things a step further.
The same source also have it that some fans came equipped with pots and pans which they started banging, while others blared car horns.
Seriously, who comes up with these ideas?! Anyway, if you see Ronaldo and co. starting to look tired tonight, you'll know why.
There was an even more impressive turnout during the day, with 700 fans turning out to welcome the Real bus. 'Welcome' probably isn't the right word, actually - take a look:
Unfortunately for Madrid, their hostile reception shows no signs of abating.
Around 10,000 fans had already made their way into the ground five hours before the kick-off, with hundreds more queuing outside.
What an atmosphere they're in for. Also boosting Napoli is the fact that Dries Mertens will be back, and their attack is going to need him.
Zidane could revert to 'BBC' now that Ronaldo, Karim Benzema, and Gareth Bale are all available again, though if truth be told, the European champions have been faring just fine without them.
Zizou can't afford to be complacent anyhow, especially not with this reception from the home crowd.
Who do you think will win the Champions League? Have your say in the comments.
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