IT is perhaps damning on Rangers’ recent recruitment policy that Kenny Miller remains a first-choice pick at the age of 37 but once again they had reason to be grateful that he is. A goal behind to Motherwell with just six minutes to play, an ignominious first-hurdle exit from the William Hill Scottish Cup loomed large. Ibrox grumbled in discontent.

Miller, though, would soon lighten the mood considerably with two timely and telling interventions to secure Rangers’ passage through to the fifth round. He is more often than not asked to patrol the wider areas these days but, with both Joe Garner and Joe Dodoo missing due to injury, there was a rare start for Miller at centre-forward. There he would again show that the best strikers are the ones who can toil for most of the game but demonstrate clinical efficiency when it matters most.

Miller had seen a Barrie McKay cross somehow scoot past him in the first half, a header clunk against the top of the crossbar, and a late dribble snuffed out by goalkeeper Craig Samson. The forward, though, is nothing if not persistent and in the closing minutes he twice got his rewards.

Rangers had been laborious in their build-up play throughout the contest but chose to go more direct after 84 minutes. It worked a treat. Substitute Martyn Waghorn swept in a left-foot cross and Miller was alert enough to dart beyond a cluster of static defenders and then stretch to divert a header into the net.

“After we got the first goal I felt very strongly that we would then push on,” manager Mark Warburton said.

His team belatedly showing a greater sense of urgency, what would turn out to be the winning goal duly arrived a minute before the end of time. There was a lot to admire about it from Rangers’ point of view, the terrific first-time through ball from substitute Emerson Hyndman and the composure of Miller who took two touches to settle himself before arrowing a strike beyond Samson.

Motherwell, though, were also largely complicit in their own downfall, Stephen McManus hurried into a snatched clearance that went straight to the lurking Hyndman. The defender’s reaction as he held his head in his hands told its own story. “Ludicrous,” was how manager Mark McGhee later described his team’s defending at Rangers’ second goal.

Motherwell’s game-plan had been to thwart and frustrate in the early stages and then look to sneak something on the counter when Rangers began to over-commit to attack. It did not make for a classic Scottish Cup encounter – lunchtime kick-offs tend to be something of a slow burner in any case – but for the opening 84 minutes of the game it had worked to perfection, the frustration audible in the crowd as Rangers struggle to prise open a seemingly watertight defence.

Barrie McKay enhanced his burgeoning reputation with another lively performance, while there were flashes of inconsistent inspiration from Michael O’Halloran on the other wing. The former St Johnstone player, wanted by Motherwell incidentally, probably should have had a penalty when one mazy run was halted crudely by Steven Hammell but referee Craig Thomson was not of a mind to award it.

“I thought it was nailed on from what we saw,” added Warburton “I’ve not had a chance to look at the replays but why would the boy go down?”

Motherwell had barely threatened the Rangers goal in the opening 74 minutes – one shot off target, another effort between the posts – which made their goal even more of a surprise. It was a well-executed move, Chris Cadden given yards of space to pick out Lewis Moult who manoeuvred himself between Rob Kiernan and Lee Hodson to plant a firm header beyond Wes Foderingham. A first Scottish Cup victory for Motherwell at Ibrox since 1961 appeared on the cards.

They hadn’t counted on Miller, however, and his two goals, although Foderingham also had a part to play by making an impressive double save from Carl McHugh and then Scott McDonald when the score was 1-1.

“You never think it’s won,” said Motherwell’s Craig Clay. “They had a bit of possession but they’d never really hurt us. We were set up well and the least we deserved was a replay.”

Instead, it would be Miller Time once again.

“When you're losing 1-0 in the cup and looking like you're on the way it's important we stick together and stick to the plan,” said the striker. "Luckily today we got our rewards.”