Lionel Messi had put Barca ahead with a penalty in the first half, but Mbappe pulled the French champions level with a classy piece of control and finishing to complete a flowing team move also involving Marco Verratti and Layvin Kurzawa
Mbappe, who had not scored in the Champions League knockouts for two years before Tuesday, smashed PSG into the lead in the 65th minute while Moise Kean took advantage of some woeful Barca marking to head in a third goal for the visitors in the 70th.
The insatiable Mbappe looked hungry for more though and after being denied a third goal of his own by Barca keeper Marc-Andre ter Stegen, he completed his treble in the 85th minute by curling the ball past the German into the top corner.
Barca overcame a 4-0 defeat to PSG in a last-16 first leg in 2017 by winning the second leg at home 6-1 but the Catalans now face another daunting task in turning this tie around when they visit the Parc des Princes on March 10.
Follow the latest reaction on our live match blog.
That’s all, folks
That’s it from us tonight – we hope you enjoyed that as much as we did.
For now though, we leave the final word to one man: Kylian Mbappe.
“It was a very important match for us. We wanted to come here and win. We did that in style. Tonight was magnificent, but we haven’t won anything yet.”
Griezmann makes Messi prediction
Antoine Griezmann, who won the 2018 World Cup alongside Mbappe for France, told RMC after the game: “We all need to enjoy Kylian, because PSG have a player who will be of the class of Leo and Cristiano.”
Koeman: ‘We lack things to be at the best level’
Barcelona coach Ronald Koeman was magnanimous in defeat, reflecting on the fact that the performances and scoreline prove PSG are a superior team.
The BBC reports Koeman as saying: “Surely the result reflects how superior they have been. In the second half we had problems defensively… they proved physically to be very superior to us.
“We have to admit that they have been superior. They have shown that they have a more complete team than us. We have to accept it, improve things. We know that this can happen because we play against a great team. physical team, with experience… for many things that is ahead of us
“A 1-4 defeat is normally very difficult. I can lie to you but losing at home 1-4, there are very few options.
“The game has shown us that we lack things to be at the best level, especially at the Champions League level.”
Mbappe in one word
Get involved on Twitter by letting us know how you’d describe that performance by Mbappe in one word…
Owen Hargreaves just described Mbappe’s performance on BT Sport as reminiscent of the “Brazilian Ronaldo… absolutely amazing” – and he’s not wrong.
A truly well-deserved match ball for Mbappe.
It seems like we may be laying it on thick, but even with Barcelona’s recent troubles, Kylian Mbappe has just destroyed one of the top teams in Europe.
And what will Lionel Messi think? Barcelona look as far away from winning the Champions League as ever since 2015, and he may well see playing with Mbappe next season as his best chance of lifting the trophy again.
Catch HiMbappe If You Can
This picture tells the story of the night for Kylian Mbappe and Gerard Pique.
Mbappe ends the match with a huge smile on his face. He walks off with the match ball and is congratulated by his team-mates. That was the sort of performance that will be talked about for years.
Full-time | Barcelona 1-4 PSG
Barca have been humbled by Kylian Mbappe tonight. What a performance from him, and from PSG. Pochettino got his tactics spot on tonight.