A late penalty from Jon Daly and a strike from Stuart Armstrong sent Dundee United into the break of their home clash with St Mirren 2-1 up.
Having started the encounter brightly, visiting St Mirren took the lead with 16 minutes on the clock when Paul Dummett turned in a cross from former Derby County winger Gary Teale.
The away team continued to dominate, but they were unable to add to their tally.
Their failure to find the net again was eventually punished just two minutes before the break.
Dummett brought down Daly inside the area and the United striker dusted himself down to convert the resultant penalty from 12 yards out.
Then, with one minute of stoppage time played, Armstrong tried his luck from 25 yards out and was rewarded when the ball found the bottom right-hand corner of the net.