When you're trailing by three goals in the second leg to one of European football's heavyweights, the chances of coming back from behind to go through to the next stage is slim, to say the least.

However, Barcelona has shown that the impossible is indeed possible, having overturned their 4-1 deficit against Paris Saint-Germain last month to claim a stunning 6-1 victory at the Nou Camp.

Tonight, the Blaugrana need to pull off a similar miracle if they are to secure their place in the semi-finals of the competition and claim a second giant scalp on their journey to the latter stages.

Six weeks ago the Brazilian bagged himself a superb hattrick on their way to victory, with one, in particular, heaping an even greater amount of pressure on his slight shoulders as it came from the penalty spot in the 92nd minute.

Having already curled in a stunning free-kick, he would have to walk the walk from 12 yards before he could be put in a position to loft a ball into Sergi Roberto for the game-winning goal.

And he has now opened up on how he was thinking of taking the decisive spot kick and what he said to himself for composure.

"When I scored the fourth, I still had hope we'd score another, even if it was just to say we had almost done it," Neymar told Esporte Interativo (via Daily Mirror).

"Then we won the penalty soon after. [Lionel] Messi said: 'You can have it. Go for it.' I knew I had to score to give us a chance of doing something extraordinary.

"I remember when I grabbed the ball to take it, I heard people saying there were five more minutes to play. At that point, I thought, 'F***, you've got to score this, or you're screwed!'

"When I scored, it was a relief. That really got the crowd going. Then came the historic goal."

However, Neymar made a revelation when he went on to confess that he thought that Gerard Pique was the man to get on the end of his lofted pass into the box that set up Barca's winner, and not Sergi Roberto.

"My first thought was to shoot," continued Neymar. "But I saw two Barcelona team-mates moving – Messi and Pique. I didn't even see Sergi Roberto. I was playing it for one of the other two. At first I thought it was Pique who had scored."