Celtic's UEFA Champions League campaign got off to the worst possible start after being thrashed by Paris Saint-Germain at home on Tuesday.
PSG ran out 5-0 winners at Celtic Park, with the Ligue 1 side's front three running riot.
Neymar opened the scoring and then set up fellow new signing Kylian Mbappe, before Edinson Cavani converted from the spot to make it 3-0 at half time.
Socceroo midfielder Tom Rogic started on the bench but was brought on by Brendan Rodgers at the break.
However, Celtic failed to threaten in the second period, with a late Mikael Lustig own goal and another strike from Cavani bringing the score to 5-0.
The other clash in Group B saw Bayern Munich defeat Anderlecht 3-0 at home.