Ivan Sproule capped a fantastic fortnight with another vital winner to push Hibs within two points of league leaders Hearts.
Sproule fired a glorious hat-trick against Rangers two weeks ago, won his first cap for Northern Ireland when they defeated England in midweek, and today he came off the bench to steer Hibs to victory.
It had looked as if Hibs had lined up very negatively with only one striker in Gary O'Connor, but they started well and might have had a penalty when Mark Kerr hauled down Michael Stewart. However, it wasn't given and United hit Hibs on the break to open the scoring after 14 minutes.
New signing David Fernandez went down the right wing and his cut-back was missed by Chris Hogg, allowing former Hibs player Grant Brebner to fire home from 10 yards.
But United's lead was short-lived when Hibs did get a penalty four minutes later after Duff blocked Stuart's run into the box. O'Connor calmly sent Derek Stillie the wrong way to fire Hibs level.
And Hibs went on to create the best chances of the first half with Chris Hogg blasting over from only eight yards before Murphy finished off a good run with a right-foot shot which was just off target.
But United might have gone in at half-time with a lead had Fernandez not been judged to be offside when he turned in a re-bound effort from Brebner's volley.
But Hibs again had most of the pressure after the break, and O'Connor was denied by a great save from Stillie at his left-hand post.
Then enter super sub Sproule to settle things with a 70th minute winner.
His electric pace carried him on to O'Connor's path and he rounded Stillie to score, despite Mark Wilson's efforts to clear off the line.
United tried to get bodies forward in search of an equalizer, but the closest they came was when Fernandez lobbed over the bar from Malkowski's poor punch