Earlier Marc-Antoine Fortune had a goal controversially disallowed for a foul on the Hoops stopper.
Celtic boss Tony Mowbray: "We played on the front foot. We pushed them back.
"I think we felt we had done enough to come away with three points.
"I thought the referee had a good game. He obviously saw a free kick against Fortune and gave it. You have to abide by the decisions.
"I am trying to build a team not just to win the league this season but for the next four or five years and hopefully our brand of football will do that in the long run."
"Celtic played very well. It was a tough afternoon for a lot of our boys.
"I felt the second half we did a little bit better.
"We are delighted to have got a point from a game we should not have. We were not with the pace of the game at all."