The pressure on United manager Ian McCall was slightly eased by this victory which puts them through to the quarter finals of the Scottish Cup and leaves behind the nightmare of a 7-1 thrashing by Rangers.
It took just 12 minutes for the Premier League side to settle as they made their breakthrough and they then proceeded to turn the screw on the Dumfries outfit, virtually killing off the game with two more goals before the interval.
They were quicker to the ball and their defenders never really allowed Queens forwards to strike any rhythm.
The first goal came after just 12 minutes when Stevie Crawford headed on for Jim McIntyre to take the ball in his stride and turn it past keeper Colin Scott from just 10 yards.
They added another after 23 minutes when Mark Wilson shot from 35 yards, and although the keeper got his hands to the ball he could only turn it into the corner of the net.
And it was all over in the 38th minute when a cross from the left was mis-hit by Willy Gibson and Stuart Duff took the opportunity to hammer the ball home from 15 yards.
And there could have been more with Mark Kerr going close with a blistering shot from the edge of the box which just flashed round the upright.
And just after the break Stevie Crawford cut in from the left, and although he lured the keeper out of goal he could only hit the side netting.