Manuel Pellegrini's men came away from Bayern Munich with a 3-2 win in the Champions League group stages earlier this season and Hart believes Man City can repeat their heroics in Spain tomorrow night.
City are 2-0 down to Barcelona on aggregate after losing to the Spanish champions at the Etihad Stadium, meaning they would need to win by the same scoreline to force extra time - or a two-goal win with a higher scoreline to progress.
But 26-year-old shot stopper Hart feels his side's win in Germany back in December gives them all the confidence they need to repeat the feat at Camp Nou.
“We’ve shown what we can do when we beat Bayern Munich away in December and while it’s going to be tough, it’s not impossible," Hart told reporters ahead of the game.
“I felt we were there in the first leg, had sized them up and were ready to go, but stuff happens in big games and if you give a predator like Barcelona a sniff of blood and unfortunately that’s what happens."
"Martin [Demichelis] was unfortunate and missed the ball by inches, but that can be the difference in games of this magnitude.”
However, the England goalkeeper also warned that Barcelona's recent league form - Gerardo Martino's side have lost two of their last three in La Liga - may not have a direct bearing on tomorrow's second-leg clash.
“Does their form have a direct bearing? It does and it doesn’t but we understand what big games do to Barcelona,” the 26-year-old continued.
“They’ve been in the latter stages of the Champions League many times before while we are relatively new to it."
“I don’t think we can read too much into their league form away from home against the lesser sides in La Liga, especially as they are at the Nou Camp against a British side with a place in the quarter-finals at stake.”