Two late goals from St Johnstone meant Motherwell tasted defeat at McDiarmid Park for the second time in a week.
The Steelmen led from the third minute but were undone by two set-plays with five minutes to go.
The away side got off to the best possible start when with only 30 seconds on the clock, Sven Sprangler knocked a the ball away with his arm inside the box and the officials finally reached the correct decision.
Andy Halliday kept his cool and sent Fisher the wrong way.
From there it was relatively positive, with Tom Sparrow – deployed in a right wing back role – getting up and down the sides, combining well with Tawanda Maswanhise but the Zimbabwean couldn’t find the target from just outside the box.
New signing Ellery Balcombe was called into action midway through the first half, palming away Victor Griffiths effort before Shane Blaney prodded the ball clear.
Into the second half, a Motherwell side that had been on the front foot, appeared to start sitting deeper, with chances coming few and far between.
Tawanda Maswanhise and debutant Luke Armstrong had decent chances but failed to test Fisher in the St Johnstone goal.
Up the other end, Balcombe had a good double save to deny Carey then Sidibeh.
The home side drew level with five minutes to go after a corner was recycled by Carey which allowed Taylor Steven to fire in Nicky Clark’s layoff.
At that point a draw might have been a fair result but the home side had other ideas. With 88 minutes on the clock, a corner wasn’t properly dealt with and Jozo Mikulic was on hand to fire in from close.