ALL but around 300 Rangers fans duly conducted their boycott of Tannadice, but for much of this match it appeared that the club's players were also making a principled objection to such rudimentary footballing basics as accurate passing, disciplined tackling and tracking runners.

Before yesterday, Dundee United had not won at home since August, but so complete was their mastery of this William Hill Scottish Cup fifth-round tie that it was almost understandable that the gloating home supporters seemed to struggle to recognise the identity of the visitors.

"You're not Rangers any more," they chanted. This comfortable victory for United, currently the Clydesdale Bank Premier League's seventh-best team, gives new manager Jackie McNamara a quarter-final tie to look forward to following defeats in the Scottish Communities League Cup by Inverness Caledonian Thistle, and by Queen of the South in the Ramsdens Cup.

The 2012-13 season will proceed without an Old Firm match and, on yesterday's evidence, the Irn-Bru Third Division side might not be too displeased about that.

This has been a chastening old season for Ally McCoist, and this might even have been worse than defeat by Stirling Albion and home draws against Montrose and Elgin City. They generally lacked sharpness and class compared to their SPL hosts, with only the recalled Scotland cap Lee Wallace managing to keep their heads above the morass, and their misery was compounded by the late dismissals of Kal Naismith and Ian Black.

There was mitigation in the fact that Lee McCulloch and Lewis Macleod were out due to injury – McCoist recalled Sebastien Faure at right-back – but it said it all that you could have pretty much substituted any third division team for this performance and no-one would have batted an eyelid.

There had been so much preamble to this match, so much agonising over the officially- sanctioned boycott of the match by fans still aggrieved at the way the Tannadice club were perceived to have treated them in their moment of crisis last summer that it was chastening to think the Ibrox club's chances were almost gone in 16 seconds.

That was how long it took for their simmering defensive foibles to backfire in the most embarrassing manner possible.

Gavin Gunning levered a hopeful long pass, Jon Daly won the flick-on, and with Emilson Cribari and Ross Perry only succeeding in getting in each other's way, Johnny Russell ran on and fired in a low finish which was close to Neil Alexander but which the goalkeeper was unable to keep out. The scoreline could hardly be said to have flattered United. Five minutes later, Russell was given the freedom of the six-yard box following a Willo Flood cross, but his header dropped wide. Then, from another Daly free kick, the 21-year-old, the subject of a last-gasp bid by Sheffield United in the transfer window, struck the bar.

Francisco Sandaza, the former United player in the Rangers ranks, had the visitors' first chance when he glanced a header wide from a Wallace cross, but this was still a mismatch. The Ibrox side's defensive organisation was all over the place from a Flood free kick, and Daly had space from which to head flick a finish beyond Alexander. Rangers could hardly get any worse in the second half, and there was a partial resurgence. Ian Black flashed a drive wide, and the out-of-sorts David Templeton had a low shot saved, but it was hardly an onslaught and, with 10 minutes left, United had made the game safe.

Substitute Michael Gardyne cushioned a header to Daly, and the Irishman cutely played in Russell to flick the ball under the advancing Alexander with ease.

All there was time for was two Rangers dismissals – young substitute Naismith getting caught up in the moment and seeing red for scything down Flood, then Black picking up a couple of quickfire bookings, the first for a foul on Richie Ryan and tussle with Gunning, the second for a late challenge on John Rankin.

The second of these may have been relatively innocuous, but the player had no complaint given the accumulation of his fouls from early in the match, and even less so when he bent down to mimic picking up and throwing a corner flag at the home fans behind the goal.