St Johnstone led early on through Callum Hendry.

"Conceding these really soft penalties is so frustrating," said Davidson.

"I'm really pleased with how the players reacted to a horrendous decision.

"We probably let it affect us against St Mirren when we had a horrendous one against us there too."

Aberdeen, with Barry Robson taking interim charge for the first game since Stephen Glass' exit, move up a place to eighth but are six matches without victory.

St Johnstone stay bottom and now trail Dundee by a point having played a game more.

"We're Aberdeen, we'll fight back," was the message from Robson before kick-off. His side had to try to walk the walk after going behind after only six minutes.

Glenn Middleton, who ruffled Aberdeen feathers all evening, stole the ball off Jonny Hayes and drove at goal. His shot didn't match the run, but Joe Lewis could only parry out to Hendry who tucked it home.

Aberdeen roared back for the remainder of the first half, but it was more bark than bite.

Scott Brown nicked the bar with a thunderous volley, Hayes flashed an effort at goalkeeper Zander Clark, and the impressive Connor Barron also went close with a curling effort on his first start.

As well as weathering the Aberdeen storm, St Johnstone had to deal with the loss of Clark, who tried to carry on after an apparent calf injury but had to be replaced.

Injuries would play a part for both sides. Aberdeen's Declan Gallagher was replaced at half-time, with Brown shuffled back to cover in the centre of defence.

That jaunt did not last long as the Aberdeen captain went off holding his hamstring just after the hour with Funso Ojo coming on to play his part in Aberdeen's patchwork defence.

After losing one key man, St Johnstone were dealt another blow when Hendry departed injured on the hour.

Aberdeen's impetus had waned until referee Gavin Duncan pointed to the spot. Booth caught Ramsay's heels, then challenged him clumsily again - this time inside the box - and while contact looked minimal, the penalty was given.

Ferguson, who has never missed a spot-kick, made no mistake.

Aberdeen could have compounded the visitors' anger further, but substitute goalkeeper Elliot Parish made a fine point-blank stop from Christian Ramirez's stoppage-time header.

Man of the Match - Glenn Middleton

What did we learn?

Aberdeen dominated possession but mostly only troubled the Saints' goal with efforts from distance. When their goal finally did come it probably was merited, but they need much more clinical performances if they are to achieve a top-six finish.

Barron in midfield is a welcome addition for Robson - and whoever the new manager will be - but Ramirez needed more service on a night where the hosts probably could have nicked a win.

St Johnstone fans might be wondering why their club Hendry depart in the summer for a six-month spell at Kilmarnock.

He now has three goals in five games, making him the most potent striker at the club. However, when he hobbled off after an hour, Callum Davidson's heart must have sunk.

The St Johnstone manager has complained about refereeing decisions a few times of late. The manner of Aberdeen's equaliser will have done little to ease his frustration.

What did they say?

Aberdeen interim manager Barry Robson: "We got caught trying to play a bit cuter and clever in the first half, but we still had two or three great chances. Second half we totally controlled the game.

"We're frustrated not to win. What I have found out is the players are willing to work and willing to try and win. And on another day we could have scored a right few goals."

St Johnstone manager Callum Davidson: "The players gave me everything they had. We had to make four changes in the game through injuries and the players dealt with it really well.

"First half we came in not quite knowing what to expect, I thought we were the better side. Second half we didn't play quite as well.

What's next?

Aberdeen head back to Fir Park to take on Motherwell this Saturday, a week after their cup exit spelled the end of Glass' tenure, while St Johnstone host Hearts (both 15:00 GMT).