Kylian Mbappe proved he is already one of the world's greatest players after netting a hat-trick in Paris Saint-Germain's 4-1 win over Barcelona, according to Mauricio Pochettino.
PSG battered Barca in Camp Nou on Tuesday, the Parisian's taking an emphatic away win into the second leg at the Parc des Princes next month.
While all eyes were on PSG-linked Messi before the game, Mbappe showed why he is regarded by many as the Argentinian's heir to the 'best player in the world' label.
After Messi opened the scoring from the spot, Mbappe went on to net a stunning treble that was completed late on with a gorgeous first-time effort that found the top-right corner, in doing so becoming the first away player to net a Champions League hat-trick in Camp Nou since Andriy Shevchenko in 1997.
Pochettino championed the Frenchman at full-time, but also urged his team to remain humble.
"We have no doubt that Kylian is one of the greatest players in the world despite his youth," Pochettino told RMC Sport.
"He has already done extraordinary things, but we must remain humble. There are 90 minutes left and they have great players. There is still a second leg."
The result gives PSG a massive advantage ahead of the second leg, though they of all clubs will be aware of what can happen when complacency sets in.
This was PSG's first trip to Barcelona since the 2017 humiliation, when they surrendered a 4-0 first-leg lead by losing 6-1 in the return leg.
As such, Pochettino was keen to stress PSG cannot get absorbed in any talk about their performance in Camp Nou being "perfect".
"There is no such thing as perfection," he added. "I am happy with the result and how we played, but we have to remain humble.
"On Sunday we have a big match against Monaco, we are already looking towards this match."
This was the first time Barcelona have conceded four goals in a home Champions League knockout match in over 23 years.
They have never progressed in a European knockout tie when losing their first game at home.