Paris: This was supposed to be the year Paris St Germain joined the European elite with a statement victory in the Champions League, yet the French champions fluffed their lines in spectacular fashion and were trampled in the dust by a Catalan juggernaut.

After swatting aside Barcelona 4-0 in an exhilarating first leg display, an incredible meltdown in the latter stages of Wednesday’s return leg ended with the home side marching triumphantly into the quarter-finals with a 6-5 aggregate win.

Qatar-backed PSG have invested heavily in a squad designed to compete at the highest level, yet once again they were found wanting against the very best and were eliminated by Barcelona in the knockout stages for the third time in five years.

“I want to apologise to the fans,” said midfielder Marco Verratti, who had been instrumental in the first leg but was a pale shadow of his brilliant self in the Nou Camp.

“We are ashamed.” Sports daily L’Equipe needed just one word to sum up the capitulation with the headline “Unspeakable”.

The statistics do not make pretty reading for PSG, who completed just four passes, three of them kick-offs, from the 85th minute as midfielder Adrien Rabiot struggled to come to terms with the shocking denouement.

“Between 3-1 and 6-1, I do not know what happened,” he said. “We were not supposed to sit back like this, it was not the plan.” PSG were furious that a theatrical Luis Suarez tumble was rewarded with a stoppage-time penalty that Neymar converted to put Barca within one goal of victory, but first-season coach Unai Emery said the game was lost elsewhere.

“The referee’s decisions were against us but this is not why we are eliminated,” the three-times Europa League-winning coach with Sevilla admitted.

Ominously for Emery, club president Nasser Al Khelaifi said: “Everyone knows that the quarter-finals were an objective and after winning the first leg 4-0 that aim was confirmed. This is a nightmare for everybody.

“Is Unai Emery still credible? This is not the moment to talk of this. After the game, we are all upset.”

PSG now face a tricky end to the season to salvage some pride and appease their supporters.

In recent years they were almost guaranteed a Ligue 1 title to soothe the disappointment of regular early Champions League exits but this time they trail an impressive Monaco side by three points.

“I hope this setback will not weigh on us mentally,” winger Hatem Ben Arfa said.