Derek McInnes decided to change his starting line up to bring pace to the game. Wes Burns started through the middle in place of Adam Rooney, and James Maddison dropped to the bench making way for the return of Dons' captain, Ryan Jack.
The visitors showed their strength early on when James Forrest bombed down the right wing. He cut the ball back for Armstrong who couldn't quite force the ball past Joe Lewis. Dembele then had another effort saved before the Dons could clear their lines. Apart from that though the home side were the better team in the opening 20 minutes and had more of the possession.
Aberdeen showed real technique and class in their first chance of the game. Considine chipped the ball forward to Burns who cut it back into the box. Hayes laid it off for Logan. His ball in found McGinn who saw his effort blocked. A great move.
Celtic, who were starting to look dangerous on the break, won a free kick at the edge of the box. A training ground move, the ball was played square for Dembele who hit the wall. An opportunity wasted from a good position. But Aberdeen found themselves a goal behind after 23 minutes when Logan's headed clearance was picked up by Tom Rogic who hit a delightful shot from outside the box with his left foot. It was a blow for the Dons, who had looked comfortable up to that point.
For the rest of the half it was a scrap for possession, which meant that chances were limited. Celtic were doing a good job of slowing the tempo of the match. After 35 minutes Aberdeen carved out a good opportunity when Hayes and McGinn combined on the right to launch a good ball into the box. Andy Considine had ventured forward and was on the end of it. His header was just over the crossbar. Considine showed his attacking threat once again when McGinn shaped for a cross. Niall fired the ball into a congested penalty box but the ball was easily gathered by Gordon as Andy couldn't quite get the power in his volley. Burns was also not far away from getting on the end of Andy's deflected shot but it was one of those afternoon's where the Dons just would not get the break of the ball.
Just before the interval Armstrong made a late run into the area and got on the end of a Rogic cross. He really should have scored but prodded the ball wide.
At the start of the second half Shinnie picked up a yellow card before Lewis made a superb save. Sinclair drifted inside from wide and after opening up his body took a dipping shot on that was pushed over the bar by Lewis who at full stretch just got his finger tips to it. This was as good a save as you will see all season.
In the 52 minute Derek McInnes then made a double substitution. Rooney and Maddison came on for Jack and McGinn.
However it was Celtic who were well on top at this stage and they should have grabbed a second.
On 54 minutes after a Celtic break, Rogic had a one on one with the keeper but Lewis made himself big and did well to deny him. The 6'5 keeper was in action again when he got his gloves on the ball when it was cut back to Dembele who was given space to shoot inside the area. Celtic were looking very dangerous. On 58 minutes Lewis saved from Rogic again but the shot did not stick. Thankfully though Sinclair slipped as he went for the rebound. The big keeper certainly deserved a bit of luck as he was outstanding today.
An hour in, Aberdeen had weathered the storm and were showing signs of coming back into it. The introduction of Maddison was at least giving Aberdeen a new lease of life going forward. Hayes was finding more space and his cross for Rooney was just headed over. Two minutes later Hayes again burst down the left and looked to get past his marker but stumbled just as a shooting opportunity presented itself. Then Hayes again broke down the left and this time looked for Rooney at the near post but his flick hit the defender marking him.
After 67 minutes a Maddison free kick was flicked on by Rooney and the Celtic defence struggled to deal with it. Eventually the ball was half cleared before Wes Burns had a great chance as the ball came back in. Gordon actually made a very good save but referee McLean blew his whistle for a foul. There was no obvious infringement.
At this point, with 20 minutes to go, Celtic brought on Nir Britton to try and see the game out. They looked happy to hold on to their one goal lead.
With 15 minutes to go Maddison picked the ball up on the edge of the area but he was quickly surrounded by hooped jersey's and his shot was blocked. A minute later Maddison tried to play Burns in but the through ball was just a bit strong.
77 minutes in and tempers boiled over in the middle of the park. Lustig had a bad foul on Graeme Shinnie and as the Aberdeen man lay on the ground Scott Brown hammered the ball at Shinnie from close range. Not surprisingly Shinnie reacted, as did Jonny Hayes and as the referee tried to keep the players apart Brown fell to the ground. Steven McLean booked Hayes and Brown and then Lustig for the orginal foul. If nothing else it fired up the crowd for the final ten minute spell.
Stockley then came on for Wes Burns to add a different kind of threat upfront. The big striker had a real impact and suddenly the Celtic defence were struggling to deal with balls put on top of them. Aberdeen built up some momentum and then with two minutes to go a moment of real controversy. Finally Aberdeen got the break of the ball and Shinnie was through. As he went in on goal Simunovic ran across him and clearly pulled Graeme back.
The Aberdeen player stayed on his feet but as his run had been impeded he could not get a decent shot away and Gordon was able to get out and make the save. Ref McLean refused to give a penalty.
As Celtic had been trying to run down the clock, five minutes of added time were signalled. The Dons were now getting the ball to Maddison and he was causing some real problems and showing some delightful skill as he waltzed past players. His deliveries from set pieces were also testing the Celtic rear-guard.
On 93 minutes Joe Lewis came up for a free kick. Celtic managed to scramble the ball clear and big Joe managed to get back up to his goal. In the final minute Aberdeen won another free kick and again up came Joe. James produced another superb delivery which saw Sviatchenko's erratic backward header having to be tipped over the bar by Gordon. From the Dons point of view the defender made too good a contact, either side of the keeper and It was a goal.
The final whistle then sounded. The Dons rally towards the end had come too late but plenty to digest and analysis ahead of the cup final in three weeks' time.