Spare a thought for Paris Saint-Germain fans this morning.How must they feel after losing 6-1 in their second-leg against Barcelona to crash out of the competition after beating them 4-0 three weeks ago?Edinson Cavani’s strike - which made it 3-1 on the night at the Camp Nou - appeared to send the French side through once and for all.Cavani’s 62-minute goal meant that Barca needed a further three goals in the remaining half an hour. And that was still the case in the 88th-minute as Neymar lined up a free-kick.But the Brazilian curled his free-kick expertly over the ball and past PSG ‘keeper Kevin Trapp before he converted a dubious penalty in the 91st-minute.The stage was set for an incredible finish and it was exactly that as Sergi Roberto latched onto a Neymar cross to steer the ball home with virtually the last kick of the game.The Camp Nou went mental as the Barca players celebrated wildly.As for the PSG players, they slumped to the ground in disbelief after they had just been on the wrong end of the greatest comeback in Champions League history.And that devastation emanated throughout the club, through to their social media team. Following their 6-1 defeat, PSG’s official Twitter account tweeted just three words after the final whistle: “Full time: Gutted #FCBPSG”.

No more words are needed.

While everyone associated with PSG will be in disbelief following their 6-1 defeat, the result could have major repercussions for manager Unai Emery.

The Spanish boss is in danger of leading PSG to a rare trophyless season with them trailing league leaders Monaco by three points.

Emery tries to explain the collapse

And, while he believes his side made many mistakes against Barcelona in the second-leg, he has pointed the finger at the referee for numerous questionable decisions.

"We have only shown our personality at times, but the refereeing with two penalties for them and the penalty not given to us has had an impact," he said.

"And then Barcelona also had the crowd dragging them home. This makes the most in-depth analysis difficult. We believed we could do it, but the referee's decisions penalised us.

"When we analyse it it is true that we have missed a major opportunity. The first half was our fault and we didn't manage to press or do things with the ball. We defended very deep and they had more chances to score. We made mistakes for the two first-half goals."

It’s going to take a while for PSG to get over this defeat but Emery will be hoping they can rally and go on to win Ligue 1 this season. If not, he is likely to be looking for a new job in the summer.