With midfielder Jason Holt ruled out by the terms of his loan agreement from the Ibrox club, Perth manager Tommy Wright handed David Wotherspoon his first start of the campaign, hard on the heels of representing Canada against Cuba.

Gerrard's red-shirted Rangers starting line-up featured two changes from the side which defeated Feyenoord in Thursday's Europa League tie, with Joe Aribo and Brandon Barker coming in for Glen Kamara and Scott Arfield.

Before kick-off both teams lined up in the centre-circle to observe a minute's silence in memory of former Gers captain Fernando Ricksen, who died this week at the age of 43 following a six-year battle with motor neurone disease

The visitors were presented with a fourth-minute opportunity when Murray Davidson fouled Sheyi Ojo 25 yards from goal.

Rangers full-back Borna Barisic converted a wonder strike against St Mirren recently but this time his left-footed effort curled wide of the target.

In the 13th minute Morelos burst onto an Aribo pass and, with marker Jason Kerr caught flat-footed, the striker was denied at the near post by goalkeeper Zander Clark, at the expense of a fruitless corner.

Soon after wideman Ojo tested Clark again with an 18-yard curling strike after sprinting away from grounded defender Scott Tanser.

The on-loan Liverpool winger edged another shot inches past the far post as the half-hour mark approached as Rangers looked for the breakthrough.

Despite their dominance, the visitors relied on goalkeeper Allan McGregor to keep the scoreline level when the ball glanced off Filip Helander's head to an unattended Michael O'Halloran in the penalty area.

The Saints winger sensed his opportunity to strike against his former team but McGregor made up ground to brilliantly block his prodded effort.

There was no way through for either side before the break, but Rangers took just two minutes to seize the initiative after the restart.

Midfielder Ryan Jack's perceptive long ball from defence was pounced upon by Morelos and the Colombian bundled Tanser aside before advancing to smash a ferocious right-footed strike past Clark.

Saints midfielder Ali McCann might have levelled immediately but the teenager scuffed his close-range effort straight at McGregor.

Rangers put the outcome beyond doubt in the 61st minute when centre-back Goldson was given time and space to guide a 12-yard header into the corner of the net from a James Tavernier delivery.

Saints, without a league win this term, began to look ragged and Clark denied substitute Scott Arfield with a full-length save before the outstanding Aribo saw a close looping range header rebound off the crossbar.

With 11 minutes remaining, Morelos departed to a standing ovation from the bulk of the 6,251 supporters.

And after surviving Saints' claims that a Davidson shot had crossed the line before being scrambled clear by Steven Davis, Gers' replacement striker Defoe underlined his quality with two clinical penalty box finishes in the space of two minutes to wrap up the win.