After soaking up the pressure in the opening 20 minutes Aberdeen settled to the task and took the lead in the 39th minute. Paton released Smith and Ross met his cross. His shot was blocked and Neill followed in with a second effort but Kiely appeared to get the last touch and helped it over the line.
The Dons then started the second half the way they had finished the first and grabbed a deserved second goal when Mark Thomas met a corner from Lee Jones and the youngster fired home. Neill could have made it three soon after but the keeper made a fine save. Celtic set up a dramatic finale when Sheridan pulled one back with three minutes remaining. The home side then threw everything at Aberdeen in the closing stages but the young reds held out for a deserved win.
Central defenders Mark Thomas and Ryan Strachan were outstanding throughout with Neil McVitie and Brian Neil also impressing but to be fair it was a great team effort and that was only the second time Celtic have tasted defeat this season.
Redweb caught up with Neil Cooper after the match for his reaction: "Celtic started the game strongly and we struggled for the first 20-25 minutes but defended very well. After that we started to get on top and passed the ball about very well. In the end I thought we were the better team and fully deserved the win. We played really well and the guys are playing with a lot of confidence at the moment. They are doing really great in training and taking that into games.
"That is two good wins back to back after beating Inverness at the start of the week. It's always difficult coming down to Glasgow to play Celtic or Rangers but I thought we played the better football today."