The former West Ham and Tottenham striker also laid on Scott Arfield for the second moments into the second period.

But Rangers boss Steven Gerrard – already without James Tavernier, Ryan Jack, Filip Helander and Greg Stewart due to injury – faced a fresh blow after Defoe slumped to the turf with no-one near him as he chased a long ball.

With Morelos nursing a calf strain of his own, Gerrard will now have to decide whether he goes in search of extra striking cover ahead of Friday's transfer deadline.

The Defoe disappointment aside, Gerrard will be pleased to see his side respond to Sunday's defeat to Hearts. They still sit five points behind the leaders with a game in hand.

County stay ninth having taking just two points from the last 18 available.

As predicted, Matt Polster was given his chance at right-back after impressing at Tynecastle. Sheyi Ojo was a surprise starter as he and Arfield came in for Joe Aribo and Jack.

Billy McKay took over from Lee Erwin in the only change to the County team defeated 3-0 by Celtic on Saturday.

But for 41 minutes it looked as though the visitors were set to have a bigger say in the title race as they set about frustrating Rangers just like the Jambos.

Staggies keeper Nathan Baxter produced a strong hand in the ninth minute to keep out Ryan Kent's low strike after Rangers' £7million man had burned past Marcus Fraser.

With Celtic ahead early in Perth, the Ibrox faithful were growing restless as they worried about falling further behind their rivals.

But out of nothing Defoe steered his team back on course.

There looked little on as Arfield nudged a Borna Barisic cross into the box but Defoe used all his predatory instincts to spin away from Keith Watson before hitting a low strike that Baxter could not handle.

The sense of relief around the ground was palpable and with the burden lifted, it was no surprise to see Rangers cut loose and add a second barely a minute into the second period.

Ojo collected from Polster and drove inside to find Defoe, whose first-time flick took the Dingwall defence by surprise but Arfield was not hanging about as he drove through the middle to poke home number two.

McKay flashed just wide of Allan McGregor's goal to give the hosts a reminder there was work still to be done.

But soon the concern around Ibrox was not for the result but for Defoe. A hush fell over the ground on the hour mark as he pulled up, with the worry growing as he was carried off on a stretcher.

The noise levels soon soared as Morelos made his long-awaited return seven minutes later. But there was no comeback goal for the Colombian as Baxter kept out his stoppage-time drive.