After a comfortable start to the game Kristian Dennis fired in a lovely volleyed opener to beat Scott Bain and send the Saints into a surprise lead, but Odsonne Edouard was laid on for an equally good finish by Callum McGregor.
Celtic failed to capitalise on it though and blunders from Kris Ajer and Shane Duffy allowed Ilkay Durmus to fire past Bain for Saints’ second.
That’s how it finished despite several changes made by Neil Lennon – including young Stephen Welsh who showed up well having been the fans’ choice pre-match to come in to the Hoops’ backline.
Here’s how the Celtic players rated using our usual ratings scale
Player ratings scale - 10: One of the best performances you've seen. 9: Outstanding. 8: Very good. 7: Good. 6: Average. 5: Poor, 4: Very poor. 3: A terrible day at the office. 2: Abysmal. 1: One of the worst performances you've seen.
A message from the Editor:Thank you for reading this article. We're more reliant on your support than ever as the shift in consumer habits brought about by Coronavirus impacts our advertisers.If you haven't already, please consider supporting our trusted, fact-checked journalism by taking out a digital subscription.
13. SUB - Tom Rogic - 4
Technically gifted, but not the game for him having to dig in and fight out a result once introduced at half-time. Photo: VINCENZO PINTO
14. Stephen Welsh - 7
Fans called for him to start and repaid that faith with a strong second half performance once on for Bitton. Photo: Ross MacDonald - SNS Group
15. SUB - Ryan Christie - 4
Second half substitute looked off the pace and a shadow of the autumn Scotland hero. Photo: Craig Foy - SNS Group
16. SUB - Albian Ajeti - 4
Saints defence dealt with former West Ham man comfortably and he couldn't affect anything in the final half hour. Photo: Craig Williamson - SNS Group