On-loan Brighton and Hove Albion midfielder Teddy Jenks delivered a late, compelling argument for a regular start.
The 19-year-old Premier League star came off the bench to deliver a superb winner in a game crying out for a moment of magic.
There was a suggestion of handball from Jenks but there is no doubting the quality of the finish.
Jenks rifled home to sink St Johnstone 1-0 and extend the Dons Premiership winning run to three games.
It is the first time Aberdeen have won three successive league matches since September last year.
For the third successive match, Dons boss Stephen Glass named the same starting XI.
However Jenks, on loan until the end of the season, has given Glass a selection headache for the next match away to Hibs on December 22.
Jenks has not started for the Dons since a 3-2 loss to St Mirren on September 26.
The teen was red carded in that game with the Dons 2-1 up. They went on to lose.
This goal to sink Saints delivered redemption for that dismissal and surely fired him back into contention for a starting slot again.
Welcome clean sheet for Aberdeen
The opportunity for Jenks to net the late winner was constructed on the foundation of a a second clean sheet in three games.
Porous for much of the season Aberdeen are now looking solid at the back.
For an indication of the level of improvement Perth was only the fourth shut-out in 25 games in all competitions this season.
The back four of Funso Ojo, Ross McCrorie, David Bates and Jonny Hayes delivered the foundation with a shut-out – although Saints were denied by the woodwork.
Aberdeen’s attacking four, so potent in the 4-1 defeat of St Mirren, were struggling to build on that defensive solidity with a breakthrough.
Supply to Ramirez snuffed out
That was due to the organisation, discipline and work-rate of the Saints’ defence.
St Johnstone’s shape made it difficult for the Dons to play through them and the passing route to leading scorer Christian Ramirez was consistently blocked off.
Aberdeen appeared to be heading towards a frustrating stalemate until Jenks delivered the vital goal.
After a cagey opening from both sides Aberdeen, who were playing patient build up football, created the first real opportunity in the 24th minute.
Trying to unlock the Saints’ defence
Attacker Jay Emmanuel-Thomas latched onto an enticing cross from Jonny Hayes whipped in from the left flank.
Emmanuel-Thomas’ 12 yard header was palmed clear by diving keeper Zander Clark.
Racing onto a poor clearance in the 34rd minutem Funso Ojo fired in as curling left foot shot from 25 yards that dipped just over the bar.
In the 37th minute Lewis Ferguson met an Ojo corner from the left but his glancing header was superbly tipped wide by Clark.
Aberdeen were trying to unlock the defence and in the 53rd minute Ryan Hedges burst down the left flank.
Riding two challenges, Hedges cut inside and slid a pass to Watkins.
Welsh international Watkins fired just wide of goal from the edge of the box.
Moments later Shaun Rooney fired in a powerful 40 yard shot but keeper Joe Lewis stretched to his ride to push it wide.
Aberdeen wasted a clear opportunity in the 60th minute when Emmanuel-Thomas played through Watkins with a through ball.
However Watkins’ 15 yard shot was weak and straight at Clark who easily saved.
Moments later Kane hit the post with a header from the centre of the penalty area.
The ball bounced off the woodwork to Ferguson who hooked it wide.
Aberdeen netted in the 84th minute when a free kick from Ojo was cleared out as far as substitute Jenks who capitalised with a superb low drive from just outside the box.
The ball appeared to strike Jenks’ arm before he shot – however it was a superb strike from the on loan teen.
ABERDEEN (4-2-3-1): Lewis 6; Hayes 7, McCrorie 7, Bates 7, Ojo 6, Ferguson 6, Brown 7, Emmanuel-Thomas 6 (Jenks 64), Hedges 6, Watkins 6 (McLennan 80), Ramirez 6
Subs: Woods, MacKenzie, Gallagher, Samuels, Campbell.
ST JOHNSTONE (3-4-2-1): Clark 6; McCart 6, Gordon 6, Rooney 7 (O’Halloran 86), Craig 6, Bryson 6, Booth 7, Brown 6, Middleton 5 (Vertainen 62), Crawford 6 (Solomon-Otabor 86), Kane 6.
Subs: Parish, Dendoncker, Devine, Moreland.
REFEREE: Greg Aitken
MAN OF THE MATCH: David Bates (Aberdeen)
