In this dress rehearsal for their forthcoming SFA Youth Cup clash, the young Tangerines had to work very hard for the three points at a wind-swept Glenesk Park today.
Indeed, they had much to thank keeper Connor Grant for their victory as he brought off a string of fine saves.
The first came after 11 minutes when he pushed a Don McShane shot round the post and from the corner he twisted to turn a Steve Crighton first-time drive over the crossbar.
Gradually United came into the game and Ross Smith headed just past after 25 minutes.
And the hosts went in front when Ryan Dow curled home a free-kick from 25-ayards after Kenny Smith had been fouled.
However, against it was grant to the rescue two minutes from the break when he came out to block Sean burns after he found himself through on goal.
Facing the wind in the second half, Grant was again the hero pulling off a great save to deny Andy Stirling and United were lucky that the rebound was knocked past the gaping goal.
Still Saints threatened and only a Kris Irvine goal-line clearance from a Burns header prevented them levelling after 69 minutes with only more Grant heroics denying McShane two minutes later.
Yet when a goal did come it was at the other end!
Substitute Cammy Howie played the ball up the left to Dale Hilson and he cut inside to fire in a shot that Jake Cunningham couldn't hold and Jordan Elfverson knocked in the rebound.
It looked all over when Saints were reduced to ten men, Crighton being harshly red-carded after fouling Dow.
However, Saints then pulled one back with the until then so reliable Grant dropping a cross which Johnathon Henry tucked away with ten minutes left.
But two minutes from time, substitute John Murray made sure of a home victory, edging the ball over the line after Dow's effort was blocked.
Dundee United: Grant, Irvine, Lee, R Smith, Shaw, Stokes, Brophy, Hilson (Murray 86), Elfverson, Dow, K Smith (Howie 68). Subs not used: Hindley, L Swanson, Colgan.