Most of the chances in the first half fell the way of St Mirren, the most notable a lovely cross into the box from Conor McMenamin which just missed the feet of Greg Kiltie. St Johnstone's only real effort came in the form of an Adama Sidibeh header which floated over Ellery Balcombe's goal.
Despite a good start to the second half for St Mirren, it was St Johnstone who struck first to level things up when Kirk fired low past Ellery Balcombe.
The visitors were dealt a further blow when defender Richard Taylor had to be carried off on a stretcher before Kimpioka put St Johnstone ahead with a neat finish from Drey Wright's exquisite pass in behind.
Mooney then grabbed his first senior goal with a lovely volley but there was more to come.
St Mirren were awarded a penalty when an Idowu shot struck the arm of Jason Holt, who had turned his back on the ball, after referee Euan Anderson had allowed play to go on following a blatant shirt-pull on Toyosi Olusanya from Jack Sanders.
After a lengthy delay, O'Hara's spot-kick was saved but the video assistant referee spotted Rae leaving his line to cut the home celebrations short.
With the Buddies captain apparently injured, Idowu took the ball from O'Hara and stuck the spot-kick in the back of the net.