An enthralling encounter at the City Ground was settled late in the second half when United showed great character to come back from 2-1 down to score twice and secure all three points.
The Tangerines had a number of first half chances and the only surprise was that they scored only once in that period through Jason Scotland, his first goal at senior level. The home side had fewer attempts on goal but McNamee managed to squeeze one in off the post past the outstretched Gallacher and the sides were level at half time.
The second period was a more even contest and both sides had chances before Scott McLaughlin netted from outside the area with twenty minutes left. An inspired substitution by Ian McCall saw Collin Samuel on and within two minutes he scored an excellent goal to level the match with just more than ten minutes left. United were lifted by this goal and five minutes later Jim McIntyre back-headed the winner.
The result puts United on 37 points, five more than last season's total, and within touching distance of fifth placed Motherwell. The goals tally for the current season is now 35 which equals last season.
Livingston: McKenzie, Rubio, Andrews, Dorado (McGovern 45), McNamee, Makel, O'Brien, Lovell (McLaughlin 66), McAllister, Lilley (McMenamin 87), Fernandez.
Subs Not Used: Main, Brittain.
Dundee United: Gallacher, Wilson, Innes, McCracken, Archibald, Kerr, Miller, McInnes, McLaren, Scotland (Samuel 78), McIntyre.
Subs Not Used: Jarvie, Dodds, Duff, Easton.