Nigeria’s defender, Ambrose Efe went down 1-6 with his team, as Barcelona handed Celtic the harshest of Champions League lessons by producing a near-perfect display to equal the visitors’ heaviest European loss.
Gerard Pique opened the scoring and Barca added two more goals late in the first half through Pedro and Neymar.
Brazilian Neymar, a £49m summer signing from Santos, added two more before the hour mark to complete his hat-trick.
Cristian Tello completed Celtic’s misery, with Georgios Samaras’s late headed goal scant consolation.
The result means Neil Lennon’s side finish the Champions League group stage with their lowest-ever tally of three points.
And the margin of defeat at the Nou Camp matches the 5-0 loss to Artmedia Bratislava in what was former manager’s Gordon Strachan’s first match in charge in 2005.
Celtic came into the match having scored 12 and conceded none in their previous two domestic games, while Barcelona had been stung by recent losses to Ajax and Athletic Bilbao.
But this was Barca at their best, inflicting Celtic’s 25th away defeat in 27 Champions League matches.