Neil Lennon insisted ahead of the season his players had lost none of their hunger and the reigning champion looked in the mood for more silverware as it made a flying start on Sunday (AEST).
Mikey Johnston grabbed the first goal in the ninth minute before Scotland international Christie took control of the contest, scoring twice before the break.
The attacking midfielder completed his treble after the interval with a second fine strike from outside the box and there was no respite for a hapless St Johnstone in the final half hour.
Olivier Ntcham, Odsonne Edouard and Leigh Griffiths all got on the scoresheet to complete the rout at a buoyant Celtic Park.
The result served as a warning to Rangers, which finished nine points adrift of its rival last season, ahead of its visit to Kilmarnock on Monday (AEST).