Messi, however, continued his dream run by scoring goals at 77 and 87 minute. "I hope he goes on and on like this forever and scores many more goals. It was a magisterial free kick", Valverde added.
Messi has lifted the Champions League four times with Barca since making his debut in 2004, although the Catalans have underachieved in the competition since last winning it in 2015.
"It was hard to make the first goal, in the second half we started well, dominating the game, but at 1-0 there was danger, with the second goal we were calmer".
The game also saw individual records being broken as Argentine ace Lionel Messi notched his eighth UEFA Champions League hat-trick thereby becoming the first player to do so.
An early kick-off at Camp Nou meant that before most of the tournament's teams had even named their line-ups, Messi was up and running, his sumptuous free-kick from the edge of the area nestling in the top corner, exactly where it was intended.
That this comes on the heels of Argentina's disastrous World Cup performance, and the clear disdain felt by Messi as he endured the drama of it all, is interesting context for another GOAT season. It was the fifth goal of the campaign for Dembele, surpassing his total from last season. He completed his first hat trick of the season after Luis Suarez set him up on a counterattack.
Those two had not played well though, and Mbappe was caught in possession just before Firmino, on as a substitute, struck the victor in the second minute of stoppage time.
Roberto Firmino scores stoppage time victor as Liverpool edge PSG in Champions League.
"Messi is normal because we always see it", Valverde said to the Champions League TV channel.
They had three good chances to take the lead and Hirving Lozano might have equalised in the second half too, had Gerard Pique not made a scrambling last-ditch block.