A goal two minutes from the end saw Stevie Campbell's side edge out Hibs in a highly entertaining encounter at Linlithgow.
Although Hibs had the chances to win it, United always looked extremely threatening on the break which indeed was how their winner came about.
Hibs made the early running and Filip Mentel was at full stretch to keep out an Alex Harris drive. And Hibs' early pressure paid off after 16 minutes when a corner was only cleared out to Dean Horribine who buried a first timer into the bottom corner from 22 yards. Midway through the half, Mentel, who sustained a knock earlier, was replaced by Phillip Anderson.
Within a minute United were level, Scott Fraser hammering home a Dale Hilson cross from 10 yards. However, but for a tremendous goal-line clearance by Ross Gilmour a minute later, the hosts would have been back in front.
And seven minutes from the break, United's substitute keeper denied Horribine's clever curler with his feet. Yet it was United who lead at the break. Ryan Gauld was brought down in the box and Jordan Moore blasted home the spot-kick.
At half-time Gregory Vignal who was making his United debut was replaced by Barry Douglas.
With Hibs on top in the second half, they were unlucky not to level when Ross Caldwell clattered the post from 25 yards. But they drew level after 65 miinutes when Harris broke clear from the halfway line and went on to confidently beat Anderson. It wasn't all one way traffic though and Gauld, John Souttar and Moore all had chances.
Only a tremendous block by Anderson in the United goal kept out a Harris header after 76 minutes, but it was United who snatched the late winner.
Following a sweeping movement up field, Dale Hilson fired in a shot that home keeper Paul Grant couldn't hold and Moore knocked in the rebound.
Dundee United: Mentel (Anderson 23), Gilmour, Souttar, Barrett, Vignal (Douglas 46), Gauld, Petrie, Fraser, Ferguson, Moore, Hilson.
Subs not used: Johnston, Lunday, Bell, Allan, M Russell.