After a bright start on Saturday, when the Tannadice lads did really well, they were knocked back on their heels by the loss of two goals in as little as five minutes.
However, five minutes from the interval Robby Feeney was played in by Ryan O'Hara and rounded the keeper to reduce the arrears.
It looked all over ten minutes into the second half by which time Hearts had scored twice more.
But the young Tangerines were far from finished, Scott Paterson toe-poking home after a goalmouth scramble with twenty minutes left.
And ten minutes later, the Tannadice teenagers were right back in contention when Paterson scored again, sliding the ball under the keeper.
Unfortunately, despite Matti Flynn going close and Kieran McAleenan being denied a penalty after he was brought down in the box, a draw proved frustratingly elusive.
United: Gibson, Milligan (McGrath 74), Donnelly, Burnett, McAleenan, Gray, Flynn, Andreoni, McCord (Russell 57), O'Hara (Paterson 57), Feeney, Sub not used Pope.
Dave Bowman commented after the match: "Almost weekly, we are facing teams that are bigger and physically stronger.
"On Saturday, we had two in the starting line-up and five on the bench who are all still at school and it is big task for them to play against full-time teams and compete.
"It is a hard learning curve for them and the full-time players in our side have got to take more responsibility to support the younger lads.
"Having said that, I wouldn't question the effort nor attitude, because for the opening half-hour, they did really well and the fact that came from 4-1 down and almost salvaged a draw speaks volumes of their will to win.
"However, that is five or six times that they have put in spirited finishes and whilst that is admirable, it would be nice if they could find themselves getting their noses in front rather than have to keep on launching rescue missions.
"However, the fact that our three best and most experienced players - Garry Kenneth, Greg Cameron and David Goodwillie who would form the spine of the team - are missing most weeks for the very good reason that they are on first team duty and is another reason why results are not going our way."