The Tangerine colts made heavy weather of beating an Accies side that played for almost an hour with ten men at Glenesk lunchtime.
The visitors had Declan McAvoy red-carded for serious foul play after 32 minutes, but even before the hosts had gone close with Ross Smith hitting the post seven minutes earlier.
And taking the lead two minutes from the interval was no less than they deserved with Scott Allan scoring a fine goal.
Picking up a poor clearance on the edge of the box, he weaved his way past two defenders before slotting the ball home form ten yards.
But instead of building on this, the Tannadice side lost their way in the second half.
Indeed, twice home keeper Connor Grant preserved that advantage as the visitors made light of being a man short.
Therefore, it was no surprise that they equalised fifteen minutes from time when Liam Fagan got a touch at the near post to Gary Gow's well-placed corner.
Parity, however, was short-lived. Two minutes later Michael Lee, almost on the goal-line turned in David Shaw's downward header from a Ross McCord corner for the winner.
Dundee United : Grant, Lee, Howie, R Smith, Irvine (Shaw 76), L Swanson (Thomson 67), Allan, Stokes, Ross McCord, Hilson, Murray. Subs not used: McCallum, Burns, W Robertson, Dow.