Kilmarnock last night racked up a fourth successive league victory at Rugby Park for the first time since March 2006, against the league leaders.
Scorers: Kilmarnock - Obadeyi (63), Connolly (65)
It was only United’s second defeat of the campaign and one which they had not seen coming. The Ayrshire club had won just one of their previous 18 meetings and United had won each of the last five yet here they were second best by a long way.
Allan Johnston’s men moved up to third place, behind Hamilton Accies only on goals scored: last season’s relegation battle is a fading memory now. They must be wondering, though, what they need to do to attract a decent crowd.
The hosts enjoyed the first clear-cut opening in the sixth minute when an inviting delivery from full-back Chris Chantler was attacked with gusto by Josh Magennis but the striker’s header was turned away by Radoslaw Cierzniak.
Kilmarnock continued to press and Magennis was denied again, this time by a blocking tackle from Callum Morris, after he had been released as a result of Jamie Hamill’s persistence.
The league leaders were on the back foot and Tope Obadeyi, Killie’s leading marksman this season, ought to have increased his tally when Manuel Pascali nodded down a corner from Alexei Eremenko, only for the winger to volley wastefully over from six yards.
Eremenko was then inches away with a free kick from 30 yards as United struggled to cross the halfway line, although Nadir Ciftci did head wide from a Sean Dillon cross in the 26th minute.
While not quite a near miss, the incident did appear to galvanise United, who gradually managed to find a toehold in the game. Craig Samson made his first contribution of note on the half-hour, rushing from his line to save at the feet of Stuart Armstrong as he attempted to latch on to Paul Paton’s through ball.
Yet they were almost caught out by a combination of dilatory defending and Eremenko’s audacity seven minutes from the interval.
There appeared to be few options available to the Finn when he collected the ball 30 yards from his own goal but, having spotted Magennis beginning to make a run, he launched an inch-perfect pass for the striker which travelled 50 yards before it reached him.
Morris ought to have dealt with the situation but allowed the ball to bounce, which presented Magennis with the opportunity to lob over the advancing Cierzniak, who found himself in No Man’s Land.
The ball arced over the Pole before bouncing up and, agonisingly for the home support, on to the top of the crossbar and over.
Ross Barbour collected the first yellow card of the evening, for a foul on Ciftci, but the more pressing news for Kilmarnock was that Samson, who had picked up a knock during that earlier collision with Armstrong, did not appear for the second half, replaced by 20-year-old debutant Conor Brennan.
United should have been putting the Irishman under pressure from the restart but they failed to test him with a shot or a cross in the opening quarter of an hour. Instead, it was Kilmarnock who continued to be the more enterprising side and Magennis was furious not to be awarded a penalty kick, claiming he had been manhandled by Morris to prevent him getting on the end of an inswinger from Eremenko.
The playmaker, though, played a crucial role when the breakthrough arrived in the 63d minute.
Latching on to a knockdown from Magennis, he hurdled a dangerous lunge from Jaroslaw Fojut before cutting the ball back into the path of Obadeyi.
The Englishman appeared to have squandered the opening with a poor first touch but he recovered to send an angled drive low behind Cierzniak from the corner of the six-yard box.
United manager Jackie McNamara immediately sent on Gary Mackay-Steven for the ineffective Armstrong when Kilmarnock struck again.
There was another assist for Eremenko, who whipped in a corner which allowed Mark Connolly to notch his second goal of the campaign with a firm downward header.
Referee Crawford Allan had irritated the home crowd from the start but their indignation reached new heights when he cautioned Eremenko for simulation, even though Fojut had caught the 31-year-old.
Brennan proved his mettle 12 minutes from time when he parried a full-blooded drive from Chris Erskine. Adeyemo snatched at the rebound, failing to hit the target.
Johnston could easily have added a third, cutting inside to create space for himself but then leaning back and firing over from 12 yards.
United goalkeeper Cierzniak also denied substitute Robbie Muirhead with a fine reflex save when another goal would have taken Kilmarnock into second place.
As it was, the scoreline flattered a United side lacking verve, vision and velocity.
Kilmarnock: Samson; Barbour, Connolly, Pascali, Chantler; Johnston, Clingan, Hamill, Obadeyi; Eremenko (Muirhead 79); Magennis. Subs not used: Brennan, McKenzie, Ashcroft, Slater, Ngoo, Westlake.
Dundee United: Cierzniak; Watson, Morris, Fojut, Dillon; Paton, Rankin; Erskine, Dow, Armstrong (Mackay-Steven 64); Ciftci (Adeyemo 75). Subs not used: Szromnik, Spark, Spittal, Smith, Telfer.