Just six days after Caley Thistle's hearts were broken in a 2-1 Tennent's Scottish Cup defeat against Celtic - thanks to 89th and 90th minute strikes - it was the Highlanders' turn to deal out an unjust result.
Just prior to Saturday's final act, defender Grant Munro was shown a red card in his 200th match for Inverness with just four minutes remaining, when he brought Barry Robson to ground.
A nervous start from the hosts allowed United an early opportunity and Sean Dillon, who looked lively on the right flank, got free from Richard Hastings, but his cross was knocked over the bar by Jon Daly.
Visiting keeper Derek Stillie was called into action on 21 minutes and he got down well to deal with a stinging Wilson shot from 20 yards.
Inverness number one Mike Fraser, who attained the position when Mark Brown left for Celtic in the New Year, looks increasingly comfortable and he pulled off a great fingertip save from Terrors' skipper Robson.
Irishman Noel Hunt demonstrated his class ten minutes before the break when he latched on to a Daly flick-on, but his dipping drive from distance looped just over the top.
The final chance of the first half came when Canadian full-back Hastings directed a header goalwards from a John Rankin corner, but Mark Kerr was equal to it and sent it clear.
Craig Levein's men enjoyed more possession after the interval without possessing the killer touch to find the net.
Hunt looked the likeliest to make the breakthrough, but two headers from Robson deliveries finished over the top.
Substitute Collin Samuel had the Tangerines' best opportunity when he was found by an intelligent pass from Christian Kalvenes, but steered his shot side, despite having time to do better.
With just four minutes left, United's Robson thought he'd snuck a winner, but as earlier, Fraser got down brilliantly to touch the shot past the post.
This was followed in the final minute by Munro's red card when his high boot connected with Robson, although opinion seemed split as to whether a straight red from referee Stephen Finnie was the suitable punishment, with defenders back to cover.
The last moment of drama came when a free-kick into the United box found Wilson, whose shot was parried by Stillie before pressure from Graham Bayne and sub Markus Paatelainen led to them setting up Wilson for an unexpected winner.