Two first half goals were to thank for Aberdeen as they came within touching distance of league leaders Celtic after the two sides played out a feisty encounter at Pittodrie, the hosts running out 2-1 winners.
A Johnny Hayes wonder strike on 31 minutes stunned the crowd as did the follow up goal from new signing Simon Chruch six minutes later. Leigh Griffiths' late consolation couldn't be built upon with the conversion coming a few seconds before full time.
Going into the game, focus was obviously on the psychological aspect which the tie beheld. An Aberdeen victory signified that the title race would be well and truly be on, while a Celtic win would have all but won the league for the fifth time in a row for the current champions.
Dons delighted with first half display
Aberdeen came fresh into the tie having been spared cup football at the weekend. Derek McInnes' invigorated Dons played a flat 4-4-2 with deadline day signing from MK Dons, Simon Church, up top partnering Adam Rooney. Ronny Deila's Celtic had been thrashed in League Cup action on Sunday by Ross County, but the Norwegian stuck with near enough the same team which played out the tie.
The visitors started confidently and racked up the possession starts from the off, however The Bhoys couldn't find a clear cut chance. Scott Brown, back in his first start since returning from injury, linked up well with Gary Mackay-Steven and Callum McGregor to then have a shot straight down the throat of the keeper. The dip came to late on the effort and it went narrowly over the bar.
With their first shot on-target in the match, Aberdeen took the lead just after the half hour mark. A lung bursting run which cut inside by Hayes allowed him to swing his left boot at a speculative effort which beat Craig Gordon at his near post. Probably undeserving of the lead, but the goal certainly helped pave the way for future dominance.
The next goal game not long after with new man Church prodding home a header from Kenny McLean following a corner. The centre-mid rose above the rest at the near post and cushioned the ball into the feet of the striker who tapped in from close range.
Just before the break, McLean could have got himself on the score sheet. After jostling through the challenges of three Celtic players, McLean released a shot which was palmed away by Gordon to the byline.
Late fight-back proved hopeless for Celtic
Two goals down and without a paddle, Celtic had to change something going into the second half. Deadline day signing from Feyenoord, Colin Kazim-Richards, replaced an uninspiring Stuart Armstrong to hook up with Griffiths.
Following an old fashioned Scottish 'stramash' inside the box following a corner, Church thought his luck was in again but his shot dragged narrowly wide of the post from a few yards out.
Kazim-Richards' introduction would go down as a positive one as the Turkish international showed what he could bring to his new team. He was dominating in the air and played headers off for runners. This prompted McInnes to switch to having three centre-backs for the remainder of the match.
Griffiths, who had been quiet for most of the game, came close with a header just before the hour mark. However, there was no conviction or direction in his effort and the ball swept by the post.
Celtic were almost made to rue the previous miss by Griffiths when ex-player, Niall McGinn, made Gordon pull off another great stop to deny the Northern Irishman. His powerful effort from distance, coming in off the left-wing made the Scotland stopper work to prevent a third.
A matter of seconds before the end, and into added time, Griffiths did get on the score sheet. The stadium became momentarily like a morgue when the striker placed the shot low into the bottom right corner of the net. Too late for any comeback for The Hoops, but the goal increases Griffiths' tally for the season.
The final whistle brought jubilation to Pittodrie. Arguably the most comfortable the northerners have ever been against their Glasgow counterparts for some years.
This weekend, Aberdeen will be looking to make it 12 undefeated in a row. They travel to Perth to play St Johnstone in what will be another test for The Dandies. Celtic will be on easy street this Sunday as they play non-league side, East Kilbride in Airdrie.