The only conventional aspect of this game was the result.

A top-flight club knocking out a fourth-tier side from the William Hill Scottish Cup is hardly unexpected, even if Rangers would have considered themselves capable of a more resilient display.

Even so, the sight of police officers erecting barriers outside the ground before kick-off, to control the flow of fans into the stadium, was an indication of the peculiarities of this encounter.

Rumours abounded of Rangers supporters' buses travelling to Dundee, even though none of the passengers were attending the match. That kind of story turned out to be misguided, but 422 away fans still broke the boycott arranged by the Rangers support and backed by the club itself, which did not take its allocation of tickets for this tie.

The Rangers players acknowledged their small band of fans, tucked into a corner of the main stand, but the Dundee United support was even more focused on them.

The atmosphere was never intimidating, because mockery seemed to be all that the United fans wanted to indulge in. Even before the game kicked off, they were singing, "You're No' Rangers Any More".

That kind of barb has become so commonplace that the Ibrox support are inclined to dismiss it. The very fact that opposition fans are agitated enough to use it is proof enough that the old rivalries remain entrenched.

United tried to make a virtue of the boycott, selling tickets for the away end to anybody who wished to buy them, and urging their own support to turn out in numbers.

The crowd of 9564 was close enough to the typical attendance of a United v Rangers game for the home side to feel vindicated, although Rangers fans will feel the same since their own grievances have been aired through- out the preamble to the tie.

"It was a strange build-up," said United striker Johnny Russell. "It's not our place to really say anything. Rangers made the decision [for the fans to boycott the game] and it was their decision to make. It's down to what we do on the park – not what goes on off it. Just because of all the stuff that's happened to Rangers doesn't mean that we don't want to beat them and they're still massive games."

An element of hype was understandable, but the reality was a fairly tame occasion. A truly intense atmosphere requires both sets of supporters to be on edge, and this was too one-sided to be fraught.

There was nothing positive for the Rangers fans to react to, after all, since the defence was so abject that United were able to casually take the lead.

The home fans sang "Who The Hell Are You?", "Are You Rangers In Disguise", and constantly asked Ally McCoist what the score was. A chant in support of United chairman Stephen Thompson was even briefly aired. They were revelling in Rangers' misfortune, although the three fans who were sitting behind one of the goals and wearing Craig Whyte masks never pulled them down over their faces.

Rangers could only muster a sense of futility, on and off the pitch. This was a muted occasion for them, and once United established their lead, the urge was only to bear the circumstances. A spate of bookings told of the players' frustrations, and once the scoreline became 3-0 in the second half, both Kal Naismith and Ian Black lost their composure. Neither was violent in their tackles, but they were ill-judged, and they deserved their punishments: a straight red card for Naismith and a second yellow for Black, who stared at the United supporters who were taunting him as he walked off, then mimicked taking the corner flag out as though he was going to throw it.

The outcome, and the nature of Rangers' display, only emphasised to McCoist how far Rangers have fallen from previous standards. The United players, though, could cherish the result. "That victory feels just as good as if [Rangers] were in the SPL," Russell said.