Liverpool had been firmly under the cosh. Allison had done everything he could to keep the score level.
It appeared as if they would crack at any moment, but they stayed strong. Their opponents PSG, meanwhile, couldn't do the same.
Harvey Elliott has only scored four goals this season, and tonight's might be the most important one. With only three minutes to go until the regulation 90 minutes were up, the 21-year-old entered the field of play and raced towards the box.
His first touch was an effort that was guided along the ground towards the goal, with the ball managing to sneak past PSG keeper Gianluigi Donnarumma to secure victory for the Reds. Not many would have predicted this outcome just before the end of the game.
Liverpool were categorically dominated, with PSG having 70% possession and 27 shots, 10 of those being on target.
The Reds struggled to get near their opponents for almost the entirety of the game. Fabian Ruiz nearly scored after 10 minutes but dragged his shot wide.
Kvicha Kvaratskhelia appeared to have opened the scoring for PSG in the 20th minute. After receiving the ball just inside the box he opened up his body well and hit a well struck effort past Liverpool goalkeeper Allison, but it was not to be as he was show to be marginally offside after a VAR check.
The next best chances for PSG came during a scramble in the box with Ousmane Dembele having a shot saved and Bradley Barcola missing two others. An inability to put their chances away would come to haunt the Parisian side.
Allison continued to stand tall for the rest of the game. Two Kvaratskhelia efforts, one free-kick and one shot from the edge of the box, were tipped around the post and a Warren Zaire-Emery chance provided a scare for Liverpool but the score remained 0-0.
Harvey Elliott then popped up in the box to provide Liverpool with a vital goal that gives them a small level of insurance for when they head back to Anfield for the reverse fixture next week.
Arne Slot won't be best pleased with how his Liverpool side played overall but he can certainly give praise to the side for their resolute last ditch defending that kept the ball out of the Reds' net for 90 minutes.
Luis Enrique, meanwhile, can take solace in the fact that he knows his side can remain on top for large portions of the game. Some more decisiveness in front of goal next week, and Liverpool could quite easily not be playing another game in the Champions League this season.
