ST MIRREN booked their place in the Scottish Cup quarter-final with a 3-2 victory over East Fife at Bayview on Saturday.
The Buddies will learn their last-eight opponents when the draw is made later today (Sunday), with only Celtic, Partick Thistle and Aberdeen in the hat along with the Paisley side. Replays will decide the other ties while Hearts face Hibs and Rangers take on Morton on Sunday.
Cammy Smith opening his Saints' account in the first half with a close-range finish after Stephen McGinn's shot was deflected into his path.
Early in the second half Saints' Harry Davis quickly went from Saint to sinner. He cleared a lobbed effort from Chris Duggan off the line before bundling Ross Brown over in the box moments later. Duggan sent the penalty straight down the middle to level the tie.
St Mirren manager Jack Ross turned to his bench in an attempt to prevent a replay at the Paisley 2021 Stadium and one of his substitutes came up trumps.
With 20 minutes to go a Saints' counter ended with Stevie Mallan playing substitute Lewis Morgan through on goal, the winger finished on the angle just four minutes after coming on.
With six minutes left Morgan wrapped things up with a moment of brilliance. He cut inside onto his right foot and fired in a terrific strike from 25 yards into the bottom corner.
The scoring wasn't finished though as to the bemusement of most in Bayview the referee pointed to the spot once again, apparently for a push in the box by Harry Davis. Duggan doubled his tally from the spot but it was the last kick of the game.