CELTIC’S opening Champions League group may ultimately, and inevitably given the eye-watering sums of money their opponents have lavished on new players this summer, have ended in bitter disappointment and crushing defeat.

This occasion, though, provided a timely and welcome reminder, at the end of a depressing few days in which all of Scottish football’s old disputes and divisions have resurfaced, of just how wonderful the beautiful game at its very best can be.

The most expensive strikeforce ever assembled, Edinson Cavani, Kylian Mbappe and Neymar, played up front for Paris Saint-Germain last night. This was more OMG than EBT.

Each member of the triumvirate helped himself to a goal in the first half as the French champions ran riot and raced into an unassailable 3-0 lead. However much they cost it was money well spent.

Saint-Germain’s world-record purchase of Neymar and subsequent acquisition of Mbappe may be under investigation by UEFA due to a widespread suspicion that it falls foul of Financial Fair Play regulations.

Yet, nobody in the sell-out crowd at Parkhead last night, not even the Celtic supporters who were willing their celebrated visitors to come unstuck, was complaining about seeing a front line which cost over £400 million taking to the field. It is an evening none of those lucky enough to be in attendance will forget.

The 5-0 loss - the heaviest Celtic have suffered at home in Europe - may have been painful for the followers of the former winners to bear. But their conquerors were a joy to behold. On this evidence they are genuine contenders to triumph in this competition this season.

Celtic have failed to overcome Juventus, Bayern Munich, Barcelona, Manchester United, Shakhtar Donestsk, Aalborg, Benfica and AC Milan in their opening Champions League group game in the past 16 years. Paris Saint-Germain were duly added to that lengthy list. But there was no disgrace whatsoever in this latest result.

The absence of both Dedryck Boyata and Erik Sviatchenko meant that young Anthony Ralston found himself promoted to the Celtic starting line-up.

The 18-year-old right back is an exceptional prospect of whom great things are expected. But he had made only six first team starts and one European appearance before last night.

The teenager, like all of his team mates, endured a torrid 90 minutes. But he certainly had his moments. He forced his way into the Saint-Germain box in the second half and was yellow carded for flattening Thiago Motta. He will benefit from being exposed to such a formidable outfit at such a tender age.

Brendan Rodgers moved Mikael Lustig in to centre half alongside Jozo Simunovic and Ralston took up his favoured berth outside him. His reluctance to put his faith in either Kristoffer Ajer or Nir Bitton was to be expected given the quality of the opposition.

But Unai Emery’s team seized control of the game from kick-off and did not relinquish it. Still, their first goal in the 19th minute was contentious. Scott Sinclair appeared to be barged over by Motta as he surged upfield. When referee Daniele Orsato failed to blow his whistle it appeared as if he was playing advantage.

However, when Leigh Griffiths lost possession play continued. Adrien Rabiot picked up the ball and sent Neymar clean through on goal. The striker scooped the ball beyond Craig Gordon and into the roof of the net.

The protests of the Celtic players and the boos of their fans were justified. It was a harsh way to fall behind after defending so resolutely in the opening stages.

Paris forged further ahead in the 34th minute when Neymar nodded a Marco Verratti cross from the right flank across the face of the Celtic goal. Cavani fresh-aired his shot but Mbappe was lurking behind him and he connected.

The Uruguayan made amends for that uncharacteristic error six minutes later when he won a penalty which he then calmly converted himself. Simunovic brought him down and the striker sent Gordon the wrong way.

Falling 3-0 behind in the first half proved too much for one imbecile who ran onto the pitch and tried unsuccessfully to kick Mbappe. The player calmly sidestepped him. The fan was apprehended by stewards and led away with the abuse of is disgusted fellow supporters ringing in his ears.

Celtic, who have been disciplined 11 times by UEFA in the past six years for similar misdemeanours, are sure to be punished for the unseemly incident. It marred an otherwise exhilarating evening.

Griffiths forced a fingertip save from Alphonse Areola with a dipping free-kick shortly after the first goal. Kieran Tierney tried his luck from wide of the left and got his attempt on target. And the keeper palmed a Sinclair shot wide just before half-time. But Saint-Germain were comfortable.

The Green Brigade had unfurled a huge banned which read “The Celtic Renaissance” just before the game got underway. There was, however, to be no revival by their team in the second half. Tom Rogic took over from Stuart Armstrong at half-time and his introduction to proceedings made a difference. The home team competed ferociously in the second half.

But Lustig turned a delivery from Julian Draxler, who had come on for Rabiot, into his own net with seven minutes remaining and Cavani added his second of the evening moments later. Celtic will not be the only team to be beaten by such a large margin this season.