Beattie smashed in his 21st goal of the 2007-08 season when he fired home a 35 yard free-kick on 33rd minute whilst strike partner Billy Sharp doubled the Blades lead eight minutes into the second half - veteran striker Andrew Cole (80) fired home a consolation for the home side and despite a brief bombardment the Blades kept Burnley at bay.
It was a truly profession al performance by United and kept their opposition out for most of the game until Cole struck home, however before the first goal came the visitors had numerous of chances to open up the game.
Star striker Beattie had already seen his close range header tipped over the bar ten minutes into the game before his powered home the free-kick after former Sheffield United and Everton defender David Unsworth needlessly bundled over David Cotterill in front of goal - drilled into the top left hand corner.
The Clarets responded well with Kyle Lafferty superbly denied by Paddy Kenny after excellent play on the right by Cole, James O'Connor also went close with a rasping shot from 20 yards.
At the other end Stephen Quinn came very close when he linked up with Beattie in the box, and there one-two saw the Irishman skim the ball wide of goal at the far post.
Robbie Blake and Kyle Lafferty both saw further shots denied early in the second half has they attempted to find a leveller, but there was no mistake when great play by United handed them the second goal.
The inform Beattied had snatched the ball from inside his own half and powered down the middle with no one in front of him, as the Clarets back four advanced the ex-Southampton man slipped through to Davisd Cotterill on the right, he twinkled past Stephen Jordon before unleashing a fantastic far post cross to the unmarked Billy Sharp who had an easy task of heading home past a stranded Brian Jensen for 2-0.
Beattie then flashed his shot wide when a chance of a third looked beckoning - but ten minutes from time former Manchester United striker Andrew Cole latched onto Joey Gudjonsson's ball through to slip the ball past Kenny to hand the Turf Moor side a life line.
The home side turned on the style and created more chances, in desperation to claim a point of the game, Kenny reacted brilliantly to deny Cole in a goal mouth scrambled as their best chances was kept out and United did enough to claim and deserve all three points in Lancashire.
The result leaves Burnley with another season in the Championship, leaving it mathematically impossible to make the top six whilst United have a slim opportunity to creep into the play-off pack.