One of the biggest talking points this summer was who Kylian Mbappe would be joining, and we finally got an answer on Deadline Day.The 18-year-old left Monaco to join PSG on loan, with the Parisians making the deal permanent for £166 million in a year's time.The striker may not have been the Ligue 1 runners-up's most expensive signing - Neymar took that title with his £198million switch from Barcelona - but it's arguably the most exciting.We all know exactly what Neymar can do, yet Mbappe is still a teenager with only one season at the top under his belt.Given that he's already being tipped as a future Ballon d'Or winner, it's expected that he'll soon be banging in the goals for Unai Emery's side.His first goal could have come a lot sooner, however, had he not displayed a classy moment during PSG's opener against Metz on Friday night.That man Neymar provided the through ball - and what an assist it was - with both Mbappe and Edinson Cavani running onto it.They couldn't both shoot, and it looked as if the French international let the Uruguayan have the shot.

Class from Mbappe 

Fortunately, Cavani did the rest, taking it round the 'keeper and finding the back of the net.

Check it out:

Twitter loved it 

Mbappe's selflessness prompted quite the reaction on social media:

If Cavani had any worries about the arrival of the precocious starlet, maybe this will have eased them.

Either way, they should make a deadly partnership.

Mbappe has told Dugout that as a youngster, he had idolised Ronaldinho during the Brazilian's time at the Parc des Princes.

And he wouldn't have looked out of place in their current line-up.

There are those who see it as a gamble that PSG are going to fork out such an incredible sum for Mbappe, but moments like this suggest he definitely has the maturity and awareness of the game to be a huge asset.

How many goals do you think Mbappe will score this season? Have your say in the comments.