Hard-working Hearts achieved a well-deserved win over their Tangerine hosts.
With the end of season fast approaching, the visitors did not play much pretty football but knew how to grind out the result.
With their first attack, Hearts took the lead in the fifth minute thanks to a gift from the United defence.
Firstly, Billy Dodds easily lost possession in the midfield to Paul Hartley. The midfielder hit a low ball into the box which Paul Gallacher believed was going to be cleared by Chris Innes only for Mark De Vries to beat both of them to the ball and hook his shot into the net from eight yards.
Stung by the goal, the Tangerines responded immediately and appeared to have equalised three minutes later when Innes headed the ball home but the goal was ruled offside.
With the Tangerines pushing further forward, referee Mike Ritchie, in the 20th minute, did not endear himself to home fans when he denied United a penalty.
As Jason Scotland headed for goal, Andy Webster appeared to clip his heels but the official waved away the loud protests.
United continued to have the upper hand in terms of possession but found it difficult to break down a gutsy rearguard. Collin Samuel should have equalised in the 30th minute when, unchallenged, he headed wide from only four yards.
It was almost disaster for United at the beginning of the second period when Gallacher made a rare error dropping the ball at the feet of Kevin McKenna but with his defence struggling, the Canadian hooked the ball wide sparing the keeper's blushes.
The Tangerines continued to drive forward. Mark Wilson's 60th minute cross was superbly defended by Robbie Neilson as Barry Robson waited to nod the ball in at the far corner. From the resulting corner, Dodds' acute angled shot narrowly missed the target.
But despite all their efforts, United went further behind and saw their unbeaten run of 11 games collapse when Webster added to the visitors tally against the run of play in the 73rd minute.
Joe Hammill's deep cross was knocked back from the byline by Scott Severin for the defender to nod the ball past the diving Gallacher.