Needing all three points to ensure the championship was in the bag, they went about the game in a manner expected of a team needing to win and one desperate to halt Celtic's domination of the league.
With so much at stake, they began like a train and it was no surprise that after Kenny Miller had missed an easy chance in the third minute, the visitors took the lead two minutes later with a fortuitous goal from Kyle Lafferty.
After superb work by the industrious Steven Davis out on the right flank, the midfielder slipped the ball through to Kris Boyd.
The striker turned and fired a mis-hit which was turned in by the controversial midfielder.
Spurned by this setback, the Tangerines then set about creating a number of chances themselves before they were hit by the sucker-punch from Pedro Mendes on the stroke of half-time.
A poor header from David Robertson in the 13th minute failed to deliver the equaliser after Craig Conway had presented him with a curling cross from left.
Then seven minutes later, David Goodwillie was too slow with a lay-off from on-loan Celt Paul Caddis as his shot spun off the legs of David Weir and into the safety of Neil Alexander's arms
As United pushed for the equaliser they were always susceptible to the quick break and the warning was there in the 38th minute when Sasa Papac pulled away down the wing and crossed for Boyd.
The striker twisted past Darren Dods but, as he pulled the trigger into the top corner, up popped Mihael Kovacevic to head the ball off the line.
But the warning was there and after taking advantage of the clearance from a foul, Mendes hit a tremendous second with a 14-yard left-volley to settle the nerves of the travelling support.
And it was both game and championship over in the 51st minute with the best goal of the game.
Breaking up a United attack, the champions threw men forward in a fast moving four-man attack.
It began with Mendes who then fed Davis for the overlapping Steven Whitaker to cross low for Boyd to run in at the far post and flick the ball in.