This result will take some of the pressure off the home side who deserved all three points.
The home side made their intentions clear from the off in a game they desperately needed to win.
A forceful run from midfield after three minutes by Jamie Smith saw him drive to the edge of the area before smashing in a low shot which was parried by Derek Stillie into the path of Barry Nicholson. But under pressure from David McCracken he couldn't find the target from eight yards out.
With 21 minutes gone United almost claimed the opener when David Fernandez sprang the offside trap to latch on to a clever ball over the top from Mark Wilson. The striker steadied himself before firing in a fierce left-foot shot which Ryan Esson parried before Andrew Considine cleared the danger.
Aberdeen passed up a great opportunity after 31 minutes when Considine, Stevie Crawford and Darren Mackie combined to give Smith a clear sight on goal. However, with time to pick his spot he shot the wrong side of the upright.
Aberdeen's perseverance finally paid off after 36 minutes. Stillie produced two wonderful saves from Smith before admitting defeat and the Dons finally broke the deadlock.
Aberdeen deservedly extended their lead after 43 minutes when Nicholson and Crawford combined to release Mackie wide on the right. His cross into the area was only partially cleared by Paul Ritchie into the path of Crawford who gleefully drove home from 12 yards to score against his former side.
With the home side now rampant they could have put the game out of sight just before the interval. Smith released the ever willing Mackie on the right but Scott Severin couldn't direct his header on target with Stillie beaten.
A wicked swerving corner from Barry Robson on 67 minutes almost brought the visitors back into the game. McCracken rose above the defenders to head powerfully goalward only to see Richie Byrne clear the ball off the line at the expense of a corner.
Esson again came to his side's rescue minutes later, this time brilliantly turning away a Garry Kenneth header with Nicholson finally clearing the danger.