Celtic chucked away two Reserve League points away to St Mirren after appearing to be home and dry with a 3-1 lead.
The home team had opened the scoring early in the second half but the hoops responded with goals from Kerr McInroy, Barry Coffey and Jack Aitchison which looked to be enough to see them through until St Mirren netted twice in the last eight minutes.
The first half was completely forgettable but within a minute of the restart Karamoko Dembele dashed into the Saints box with a trademark dribble but the referee chose to ignore a pull on his jersey.
In the 48th minute St Mirren went in front from a breakaway that ended with an unstoppable shot from Matty Grant flying high into the net.
Dembele was causing St Mirren all sorts of grief as he raced down the right flank, but it was captain McInroy who drew Celtic level in the 53rd minute with a 22 yard shot that picked up a deflection on route to the net.
Celtic kicked on from that with Coffey timing his run perfectly to head home from eight yards out in the 59th minute after Dembele had hit the bye-line.
It looked as if the points had been wrapped up in the 73rd minute when Aitchison drilled a low shot into the net after good build up work down the left from Daniel Church and substitute Grant Savoury.
There was no hint of a St Mirren comeback but in the 83 minute a free kick flighted into the penalty box was headed into the net. Two minutes later Celtic keeper Ryan Mullen took a touch on a back pass from Tony Ralston that allowed Lewis Jamieson to block his clearance with the ball flying high then falling to the Saints striker to shoot into the net to level the match at 3-3.
CELTIC: Mullen,;Ralston, Duffy, Welsh, Church; Coffey, McInroy(c), McLaughlin, Oko-Flex Aitchison Dembele
SUBS: Willison, Mazis, Deas, Savoury, Caffrey, Diver.