The reserves made it two wins out of two thanks to a last minute goal by player/boss Craig Brewster.
But coach Tony Docherty didn't feel this performance matched the quality of the one against Rangers the previous week.
"It was great to get a result, but though we started well, and got an early goal, we never maintained that level of performance.
"The main problem was that when we got possession we kept giving it away cheaply.
"We lost a freak goal early in the second half and though Falkirk had more of the ball, they only really threatened once, but Euan McLean came to the rescue with a marvellous save.
"Having said that, we had what looked a stonewall penalty for handball rejected, so perhaps our last-gasp winner wasn't that undeserved.
It followed a good move in which Steven Robb was instrumental, and the gaffer finished off.
The main positives to come from the game apart from the result were the form of David Robertson in supporting the gaffer in his loan striking role and great attitude of Stuart Abbot and Barry Callaghan when coming off the bench."
The side lined up (4-5-1) - McLean - Proctor, Kenneth, Gardiner, Easton, Burnett (Callaghan 75) - Conway, Massassi (Abbot 86), Robertson, Robb - Brewster.
Subs not used: Gibson, Andreoni, Feeney.
Polish trialist midfielder Marcel Licka couldn't be fielded, as his clearance hadn't come through.
And it was the other trialist, Moroccan Abderrahmane Massassi who opened the scoring with left-drive from the edge of the box that found the bottom corner thanks to a slight deflection after only five minutes.
Fifteen minutes later, Mark Twaddle clattered the post with a fierce free-kick from almost 30-yards.
Despite that, United could easily have gone in at the interval two up when boss Craig Brewster cleverly played in newcomer David Proctor in on goal but Dutch keeper Jeron Lambers came to the visitors' rescue on the stroke of half-time.
After that let-off, the visitors enjoyed more good luck three minutes after the re-start.
Clearing a loose ball, David Proctor hit the prostrate Stephen O'Donnell and the ball reared up in the air and dropped in at the far post!
Although Falkirk had the better of the second half, they again enjoyed the rub of the green midway through the half when Mark Twaddle handled as he attempted to clear a free-kick into the box, but no penalty was forthcoming.
And with 18 minutes left, only a finger-tip save by Euan McLean from Mark Stewart's well-struck shot prevented United going behind.
However, in the final minute, Falkirk's earlier good fortune ran out when a surging Steven Robb run culminated in Lambers only parrying his shot and Craig Brewster casually tapped home with what was almost the last kick of the game.
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