Maciej Zurawski hit four goals as Celtic coasted to their biggest win under Gordon Strachan.
It was the perfect tonic before the teams meet again in next month's League Cup final, but utter humiliation for Dunfermline.
It was all over by half-time as Celtic led 4-1 against a Dunfermline side who offered only token resistance.
The opener came after just three minutes when Mark Wilson picked out Stilian Petrov and he scored at the near post.
A mistake from Artur Boruc gave Dunfermline a glimmer of hope when Andy Tod headed home 11 minutes later.
But the alert John Hartson prodded Celtic back in front midway through the first half after good work from Zurawski.
The Pole then took matters into his own hands with a crisply-struck third goal after 31 minutes and, five minutes from the break, he beat Bryn Halliwell again.
Zurawski was just inches away from connecting with a Wilson cross in the 54th minute as he tried for his hat-trick.
It came a minute later when he was left unmarked as Hartson gave him the ball and he made no mistake.
Darren Young should have pulled a goal back midway through the second half but shot straight at Boruc.
Shaun Maloney then scored the best goal of the day with 16 minutes left when he took a pass from Zurawski to volley in an unstoppable shot.
Neil Lennon even scored a rare goal with eight minutes remaining, with Halliwell slow to react.
Zurawski completed the scoring with a simply finish after beating Tod for pace.