Given the opposition, a team featuring arguably the greatest ever soccer player in Messi, this will likely rank as Liverpool's greatest European performance, rivaling the comeback from three goals down against AC Milan in the 2005 Champions League final.

There was also the 3-1 win over Saint-Etienne in the 1977 European Cup and the 4-3 win from 2-0 down against Borussia Dortmund in the 2016 Europa League quarterfinals.

For Barcelona, it was the second year in a row that it let a three-goal lead slip, having beaten Roma 4-1 at home in the quarterfinals in 2018 before losing the return leg 3-0 to go out.

Liverpool manager Juergen Klopp had delivered a stirring speech on the eve of the game, telling his players to "fail in a beautiful way" if they were to get eliminated.

They took that to heart.