Mihael Kovacevic’s ordering off with twenty minutes remaining looked to have opened the door for Walter Smith’s men, but they couldn’t find a way past the United rearguard.
It leaves the title chasing Gers needing Celtic to drop points if they are to go on and clinch the SPL against Hearts on Sunday.
Smith made just one change in personnel with Madjid Bougherra replacing Danny Wilson, but there was a tactical switch too.
Steven Naismith moved from the forward role he occupied against Aberdeen seven days earlier to the left midfield position.
That meant a move to the forward areas for Kyle Lafferty after he notched against the Dons – the Ulsterman partnering Kenny Miller.
A less than inspiring first half enjoyed its best moment just six minutes before the interval when Miller waited for the ball to drop to him on the edge of the area and sent a fine volley toward goal.
It looked to be dipping just under Dusan Pernis’s bar until the keeper got to it right in the corner of his goal frame to force it behind for a corner.
It says much for the first period that was the first time Rangers had called the home keeper in to action in earnest.
Things had started in a promising manner with Lafferty dropping deep from his forward role to pick the ball up on the left and give Mihael Kovacevic a real test.
The full back was no match and it took a foul to stop the Ulsterman in his tracks as he advanced on the United box.
From the resulting set piece Lafferty’s international colleague Steven Davis sent a curling free kick narrowly over the bar.
The left flank was an avenue of attack that the Light Blues were keen to explore, with Naismith against testing Kovacevic with some direct running.
He showed the defender a clean pair of heels but his final ball aimed at Miller was comfortable cut out by the home defence.
Rangers had started the brighter but Allan McGregor was called in to action to keep the score level after 16 minutes.
After McGregor’s defence had done well to block two United efforts, the second of which was a decent attempt from Morgaro Gomis, the ball dropped to Garry Kenneth.
The centre half was some distance out but the swerve on his shot had McGregor concerned and the keeper was pleased to push the ball away with his feet.
At that stage United switched David Robertson from their left to their right to nullify the Gers threat down that flank and the tactical switch took much of the impetus out of the game.
McCulloch and Edu were busy battling for possession in the middle and while there were glimpses of a promising partnership between Miller and Lafferty, all too often the service to them wasn’t great and their understanding still in its infancy.
The game endured something of a lull until Danny Cadamarteri’s shot in to the side netting from just inside the Rangers box seemed to spark things to life.
And it was the visitors who enjoyed the better of things in the dying stages of the opening period, with Miller’s volley the closest they came as they finished the half strongly.
In the early stages of the second period the Light Blues looked to turn that spell into something tangible.
But when Lafferty found himself clear in the United half he opted to shoot rather than roll in Davis on the right who looked to be in a much better position.
Things weren’t quite clicking for Rangers and Smith chose to introduce Boyd with just less than an hour gone in the game.
The striker replaced Naismith and seemed to turn Rangers more on to the front foot immediately after his introduction.
That forced United in to a spell of counter attacking and when Jenison Myrie-Williams’ progress was halted by Sasa Papac the Bosnian became the first man in to the referee’s book.
Brian Winter was to be a busy man midway through the half when Lafferty and Kovacevic tangled.
After a warning from the ref for both players they continued their battle and when Lafferty won the ball back Kovacevic took a wild swipe at the forward.
There was no doubt he deserved the red card that followed, with Lafferty picking up a yellow for the initial challenge that won the ball back.
Going down to ten men forced United on to the back foot as Keith Watson replaced Myrie-Williams soon after the ordering off.
Walter Smith followed suit with Lafferty quickly replaced by Nacho Novo – his 250th appearance for Rangers – as the Light Blues looked to make the most of their man advantage.
United too were seeking a late winner and threw on David Goodwillie in place of Fran Sandaza.
But they almost presented their visitors with a simple winner when Kenneth’s short pass back was pounced on by Boyd.
The Gers No.9 tried to poke it home but Pernis did well to break from his line and smother the chance.
However it wasn’t to be for Boyd and his team mates as they continued to knock on the door.
When they did manage to force the ball home through Novo, the linesman’s flag was already raised and the goal wouldn’t count despite Miller’s protestations.
The striker then thought he had won it for his side in the dying minutes when he broke free and beat Pernis with a low left footed effort only to see it come back off the post.