Derek McInnes had called for Aberdeen to make Pittodrie a fortress again this season.
Instead the Dons rolled down the drawbridge in the second half to let Premiership strugglers St Johnstone over the moat to drop vital points at home.
It could have been worse had referee Steven McLean not owned up to wrongly awarding Saints a penalty before rescinding his initial spot-kick award.
A frustrating day dogged by a lack of creativity and urgency in attack was made all the more agonising with three fresh injuries.
Aberdeen face a midfield crisis after summer signings Craig Bryson, Funso Ojo and Jon Gallagher all sustained injuries.
It was the latest blow following the cruciate ligament injury sustained by Scott Wright in training that is set to rule the 22-year-old out for the rest of the season.
Aberdeen’s midfield was disrupted and Saints capitalised by controlling the centre of the park, with Jason Holt particularly influential.
But it was in attack that the bid for a third straight home league win broke down.
In the build-up to the game McInnes had called for a repeat of the clinical attacking intensity that produced the 3-0 defeat of Ross County.
Instead they delivered the blunt lack of creativity that had resulted in shooting blanks in four of five games before beating County.
Striker Stevie May, at £400,000 the most expensive signing during McInnes’ six years at the club, made a quick return to Pittodrie.
May had the final two years of his Pittodrie contract cancelled three weeks ago to pave the way for a move to St Johnston having netted just eight times in 74 games for the Dons.
May had not scored this year with his last goal coming in Aberdeen’s 4-3 loss to Celtic on Boxing Day – and that was a penalty.
As was the case in his time at Pittodrie there was plenty of effort and desire from May but at no point did he threaten to end that long scoring drought.
The woodwork denied Aberdeen in the 17th minute when Sam Cosgrove met a cross from Greg Leigh but his header hit the base of the far post.
Aberdeen went ahead in the 28th minute when Leigh burst forward at pace. He was tackled with the ball cannoning off Lewis Ferguson into the path of Ryan HEDGES who clinically fired a left-foot drive beyond keeper Zander Clark from 15 yards.
Aberdeen hit the self-destruct button in the 43rd minute through a combination of poor defending and a rare slip-up from keeper Joe Lewis.
From the left Tanser found Michael O’Halloran unmarked outside the box and he was given too much time to strike a low shot which squirmed between the diving Lewis’ hands.
Early after the break Saints’ Davidson twice threatened when heading wide and then having a vicious 12-yard drive well saved by Lewis at the near post.
Saints were enraged in the 64th minute when they were given a penalty – then had the spot-kick rightly taken away from them.
Referee McLean pointed to the spot after Kennedy went down when running across Andy Considine. If there was any contact it was minimal and it was Kennedy who clipped Considine.
So rare in Scottish football, the referee was open to the notion that he could be wrong and used common sense. There were no flying pigs among the seagulls swooping over Pittodrie.
Following consultation with assistant Graeme Stewart on the touchline, McLean overruled his initial decision.
Aberdeen were denied by a superb save from Clark in injury time when Ferguson’s powerful 30-yard free kick took a defection off the defensive wall but the keeper adjusted.