MESSI's first goal was a free kick which he curled over the wall and into the top corner of the net.
Pulling the creative strings from the centre of the park, Coutinho dictated the style of Barca's play and set the tone for the tempo of the match, majestically drifting across the pitch, spraying passes and pressing with great alacrity.
PSG had come back from two goals down with Kylian Mbappe equalising in the 83rd minute after Thomas Meunier's 40th minute strike halved the deficit.
The former Liverpool man was sensational tonight, and his link-up play with Lionel Messi was a sight to behold as the pair played with a telepathic understanding of each-other.
He scored the opening goal with a brilliant free kick in the first half and added two more in the final 15 minutes after Ousmane Dembele's solo effort as Barca ran out 4-0 winners.
Daniel Sturridge opened the scoring for the Reds in the 30th minute with a fine header from an Andy Robertson cross.
Asked about Barca's desire to end the dominance of their arch rivals and win the competition themselves, he said: "Who is not motivated for the Champions League?".
However, no interested party made a bid to sign him after the conclusion of the tournament and so he remained with his current side.
There were dramatic late goals around Europe, including for Inter Milan against Tottenham Hotspur, and winning starts for several of the leading contenders, with Atletico Madrid battling back to beat Monaco.
Diego Costa equalised for visitors on 31 minutes before defender Jose Gimenez headed home the victor from a corner on the stroke of halftime.
Schalke marked their return to the competition after a three-year absence with a 1-1 draw at home to Porto.