Killie had a man advantage after Lee Miller was sent off for his second booking five minutes before half-time, but they rarely looked like taking all three points.
United enjoyed the better of the early play, with Kilmarnock giving away possession far too easily. Despite having the lion's share of the ball, United could not force a serious save from Graeme Smith.
The closest the visitors came to a goal was in the 16th minute when the impressive Barry Robson beat his man and crossed deep to Collin Samuel. He headed back across goal, but James Fowler was in the right place to clear ahead of Stuart Duff.
The impetus of the match changed in the 39th minute when United striker Miller was shown his second yellow card and was sent off following an elbow on Frazer Wright.
United held out comfortably, but the introduction of Stevie Murray seemed to offer the home fans new hope.
The tiny winger's trickery and telling crosses stretched United, but Danny Invincibile failed to find enough power on his headed attempts.
Craig Brewster introduced new signing David Proctor for the last quarter hour, and he almost saw his side sneak the lead. Half-time substitute Noel Hunt spun clear of the defence, but slid his shot agonisingly wide of the far post.
Killie kept going and Christian Kalvenes produced a brilliant last-ditch tackle to deny Stevie Naismith a clear shot at goal.