Disappointing in the first half, United were nothing short of appalling in a destructive 10-minute spell immediately after the interval as their 100% league record was torn asunder by a callow Rugby Park XI. Energetic and eager, the hosts merit mention for the clinical way in which they seized the initiative, but to suggest that their victory was brought about by anything but United's own haplessness would be inaccurate.
Take the first of the three goals. There appeared to be little danger as Barry Douglas assumed possession but inexplicably opted to dribble across his own box before leaving the ball for goalkeeper Radoslaw Cierzniak to clear.
However, the startled Pole was unprepared, enabling Rory McKenzie to dart between the two and prod across the goal-line. "Barry is a young boy learning the game, but one of the first things you learn is not to run towards your own six-yard box," said a vexed Houston. "You can't blame the keeper because Barry hasn't even passed it to him, he's just left it."
Douglas was, understandably, rattled and caught out of position just moments later when Danny Racchi rampaged down the right. As the midfielder approached the box, a desperate Gary Mackay-Steven – playing ahead of knee surgery on Tuesday – tugged his arm and, although the initial contact may have been outside the area, Crawford Allan awarded a penalty. Borja Perez calmly rolled it in.
By that stage, United's heads were all over the place. That Kilmarnock recognised as much and sought to bolster their advantage is to their great credit and they were rewarded in the 55th minute. Racchi's corner was headed towards goal by Michael Nelson and, as the United defence panicked, Jude Winchester held off the attentions of his team-mate McKenzie to force in.
"The goals we gave away were a joke. They didn't have to work hard for the points," added Houston. "It's a reality check for us because maybe the players have been believing the nice things that have been said about them. Maybe they think they are better than they are."
Indeed, even before they resorted to self-harm, United had been afflicted by a curious lethargy. Starting the campaign with consecutive 3-0 victories had perhaps inflated expectations, but the coruscating exhibition of the opening day against Hibernian was not replicated in the Dundee derby last weekend and was again desperately lacking yesterday.
Despite the inclusion of Johnny Russell – his suspension having been rescinded after last weekend's red card – and Mackay-Steven, the visitors were ponderous in possession and anaemic in attack; consequently they were left to rely on set-pieces – a Douglas free-kick that Kyle Letheren flicked over – and hopeful balls towards the well-marshalled Jon Daly. The striker did, on occasion, bustle himself into profitable positions, but found his finishing erratic, cushioning one volley from a Willo Flood cross over the bar and flashing another across the face of goal from a John Rankin delivery.
The United captain would finally breach Letheren's goal with 12 minutes remaining, controlling a Douglas cross before sliding it into the corner, but even the late flurry that followed could not disturb a robust Kilmarnock defence.
With that resolution, though, came the sacrifice of their own ambitions, especially of the first half. Deprived of Gary Harkins, stretchered off after suffering a head knock inside the first 15 minutes, the hosts often lacked either the nous or the numbers in the final third to cleave open a defence which, at that stage, had yet to concede a league goal.
Perez assumed the creative responsibility and embroidered plenty of fine passages but, too often, a final pass was absent, with the closest Kilmarnock coming beside the three goals – second-half shots from McKenzie and Winchester – both stemming from further United mistakes.
Not that Kenny Shiels was minded to muddy the waters. "The rain at half-time was a big help because it meant football would be the winner," explained the Kilmarnock manager. "Our arrangements in attack were very good, as were the young kids. That gives me more satisfaction as a manager because you take a risk with them, but when it works and they play well you can feel the energy from the stands."