Ayorinde's extra time strike was enough to see of Nuneaton after Parr's late goal earned extra time for the Celts.
The whole game was quiet, and only burst into life in the last quarter of an hour when Charles put the home side ahead. Celtic responded with Parr's header on Turley's inch perfect cross five minutes form time putting the tie into extra time.
Neither side looked like breaking the deadlock until Celtic broke through, and Ayorinde found a chink with a rolled ball into the corner.
The second half of extra time was all about Celtic defending, and defending in depth and numbers, taking the Celts through to the next round.