Robbie Feeney's 53rd minute strike extended Stevie Campbell's side unbeaten run to six games at Glenesk Park this afternoon.
Equally as impressively, another clean sheet means it is 452 minutes since the defence conceded their only goal of the campaign.
Indeed, despite having to re-shuffle the pack, not once, but twice, this was another trademark rock solid performance by the defence with keeper John Gibson rarely stretched.
The first half was very even and almost devoid of goal scoring chances. Indeed, when Gordon Pope got in a free-header from a Scott Paterson corner but sent it over the bar with four minutes of the first half left, it was the first time that either side had really threatened. And a minute later a Scott Mathieson shot was deflected inches wide by David Gormely.
Motherwell's only intrusive excursion into the United box came shortly before the break when Alex Donnelly engineered a good position, but slipped as he pulled the trigger and the ball went harmlessly wide.
After that very even first half, it was a different story in the second half as the Tannadice teenagers dominated.
Only a tremendous fingertip save from Martin Alan prevented 'Pongo' McCord's diving header from a Fraser Mulligan cross from counting two minutes after the re-start.
But six minutes later, 'Pongo' laid the ball into Robbie Feeney who finished clinically with a low-driven shot into the bottom left-hand corner from just inside the box.
In the closing stages, United twice went close to increasing their lead. Eight minutes from the end, Neil McMechan spotted Alan off his line and hit the top of then bar from some 40-yards! A minute later Gordon Pope was afforded time to shoot from close range but his effort was blocked.
All in all, it was another well-deserved, if hard fought victory that keeps the Youth team's magnificent start to the season going.
United: Gibson, Milligan, Pope, McMechan, McGrath (Mathieson 27), McCord, Paterson, Andreoni, Feeney, Jeffrey (Love 90), Fleming. Subs not used: Russell, O'Hara, Gray, Allan.
Stevie Campbell said after the game,
"I am absolutely delighted with the lads, not only for the victory, but also for keeping yet another clean sheet under difficult circumstances. With Michael O'Byrne out injured I had to draft in Philip McGrath even although he himself has only just returned from injury. Unfortunately, he lasted less than half an hour before feeling his back injury again - though thankfully not too badly.
"That meant switching things about with Gordon Pope going into the left side of central defence and Sean Fleming dropping back to left-back with Scott Mathieson coming on and slotting into the midfield.
But I am delighted to say that made little difference to the defensive solidarity that we have shown all season.
"And after the way that we went on to control the second half, I don't feel there is any doubt that our fifth successive win wasn't thoroughly deserved."