Neymar led the way in Paris St-Germain's opening Champions League group win as Celtic sustained their heaviest ever home European defeat.
The world's most expensive player coolly finished and then had a hand in PSG's second, which was finished emphatically by Kylian Mbappe.
Edinson Cavani converted a penalty for the visitors' third before the break.
Mikael Lustig's own goal was followed by Cavani's second of the night, a diving header.
Elsewhere in Group B, hosts Bayern Munich won 3-0 against Anderlecht, who had a man sent off.