The second division outfit earned a replay against the champions after a last-gasp Steven Doris free kick cancelled out a bizarre own goal by Alex Keddie.
And speaking on Sky Sports News, Christison, whose side face a trip to Raith Rovers if they see off the Hoops, refused to rule out another shock when the teams meet again at Gayfield next week.
"It was absolutely amazing to have earned a replay against Celtic," he said. "My phone has been ringing off the wall since the game, such was the interest in the match.
"As to the replay, stranger things have happened. You only have to look at Celtic beating Barcelona a couple of weeks ago.
"We will park the bus when they come to our place next week, then who knows, a quick breakaway and we can do what we did last weekend."
On the prospect of a bumper pay-day for his club, Christison admits live TV will determine the size of the purse from Tuesday's match.
"Financially, this is only huge for us if the TV companies take the game. If they hook onto us that's what makes the difference at our level.
"As for the tie itself, we're not looking any further than the Celtic match. We'll just take it one game at a time.
"However, if we do meet Raith we'll look forward to is as we have a number of good friends down there and I'm sure they'll make us welcome."