Saints had to come back from two down to preserve their unbeaten home record.
"Crazy defending" was what home boss Gus MacPherson blamed Queens' two goals on.
A flurry of corners for Saints culminated in Kevin McGowne striking the bar with a header, but Queens survived the opening onslaught and, prompted by Brian McLaughlin, came more into the game.
McLaughlin himself brought a splendid save out of Craig Hinchcliffe from his volley courtesy of Willie Gibson's cross.
Kirk Broadfoot also hit the bar with a shot from outside the box before Derek Lyle had a wonderful chance to open the scoring when another Gibson cross evaded the St Mirren defence, but his header was straight at Hinchcliffe.
After the interval Saints strove to take control, David van Zanten and Hugh Murray going close but, in the 52nd minute, McGowne and Andy Millen blundered, leaving the ball to one another, and presented Lyle with a marvellous chance to bear down on goal and stick the ball beyond the exposed Hinchcliffe.
Two minutes later, McLaughlin released Steve Bowey with a clever flick and the Durham-born midfielder raced clear without being challenged to beat Hinchcliffe with a low angular shot.
The lead was reduced soon after. Substitute Mixu Paatelainen played the ball to Broadfoot, who rounded Colin Scott and scored from a tight angle.
Saints laid siege to the away goal and Bowey cleared a Broadfoot header from Mark Crilly's corner off the line.
Broadfoot would not be denied and, 16 minutes from time, he slotted in a low shot after Queens had failed to clear properly a header from Paatelainen.
Both sides pressed for the winner but after ref Toner had allowed four extra minutes for Scott's time wasting - which brought the keeper a yellow card - Queens secured the point they had come for.