Ten man St Mirren left Celtic on the wrong end of a 7-0 scoreline as the Bhoys went goal crazy. Shunsuke Nakamura hit a hat-trick and Scott Brown a double. Marc Crosas and a John Potter own goal completed the rout.
Celtic boss Gordon Strachan said, "I enjoyed it today. It started off at a good pace and we moved the ball well.
"We got our midfielders into good areas and caused them a bit of problems.
"Obviously, when they went down to 10 men, it caused problems for St Mirren and we got more space than we would normally get against them."
"It's always difficult when you come to Celtic Park, but when you go down to 10 men, it makes it doubly harder," said a despondent St Mirren manager Gus MacPherson.
"To lose a full-back with the experience of Jack Ross, who is probably our most consistent player this season - and a defender coming to Parkhead, makes it very difficult for us.
"We'll look at the goals again, because I think quite a few of them were individual mistakes - especially the first one."