It was the Tangerines who started the better creating the first opening with seven minutes on the clock.
A neat move between Barry Wilson and Grant Brebner ended with David Fernandez smacking a low 16-yard shot off the base of the post.
Another great ball from the industrious Fernandez in the 18th minute really should have been put away but the experienced Billy Dodds deflected the ball away from Lee Miller.
Miller's 28th minute free-kick forced a good save but it was the visitors who almost opened the scoring a minute later when Liam Fox's shot was spilled by Derek Stillie.
With half-time approaching Craig Dargo had a shout for a penalty rightly rejected and then Jim McIntyre's volley was superbly saved at the near post by the reliable Mark Brown.
The second period began with Caley looking the more threatening and they were unlucky in the 55th minute when Dargo's goal was disallowed for offside.
Then an exquisite 58th minute Craig Brewster chip was matched by a magnificent leap from Stillie.
But it was the Terrors who went ahead against the run of play in the 66th minute. Fernandez teed up Alan Archibald whose curling cross was met by Miller at the far post to nod the ball in.
However, Caley got their deserved equaliser six minutes from time. Ex-favourite Brewster outjumped United's two central defenders and bulleted in a header from Wilson's inviting cross leaving the Tannadice faithful to jeer yet again at the final whistle.