After appearing to take forward strides in recent weeks, this defeat sends Rangers backwards.
The faintest of hopes of a title challenge after reducing Celtic’s lead to nine points last weekend will disappear quickly.
The fact their first shot on target did not come until the 42nd minute, an effort on the spin from Hamza Igamane, tells the story of their woeful first half.
Philippe Clement’s team selection will come under scrutiny, given Nicolas Raskin’s urgency in midfield and Danilo’s danger in the box upped the ante following the interval.
The Brazilian striker’s equaliser came after James Tavernier curled a free-kick just wide before Vaclav Cerny smashed the frame of the goal.
But Rangers failed to take advantage when they smelled blood from their opponents, something their city rivals seem to have no issue with.
And the Ibrox side always seem to give you a chance when games are in the balance.
That was apparent again in Paisley as Dujon Sterling was dispossessed cheaply in a dangerous area in the build-up to St Mirren’s dramatic winner.
