Celtic ended their pre-season foray to France with a 4-0 friendly defeat by Paris Saint-Germain at the Parc des Princes.
Striker Kylian Mbappe had the home side ahead in the first minute with a smart finish and in the 25th minute Brazilian superstar Neymar added a second.
PSG made wholesale changes for the second half but if anything increased their control with two of their substitutes, Marco Verratti and Ander Herrera, combining three minutes after the restart for the latter to fire in a third.
Pablo Sarabia added a fourth in the 66th minute with a stunning volley and the French champions ran out easy winners.
Neil Lennon's side went into the game following a 2-1 defeat to Lyon and a 1-1 draw with Nice in the Veolia Trophy tournament but this was a huge step up from which they can take added fitness and sharpness.
Celtic begin their quest for their 10th successive Premiership title at home to Hamilton on 2 August, safe in the knowledge they will not face this level of opponent in Scotland next season.
The Hoops had lost 7-1 at the same venue and 5-0 at Parkhead when the clubs met in the Champions League in 2017.