Andy Halliday also struck as the hosts booked a last-eight date with Aberdeen at Pittodrie on March 3.

Kilmarnock with their well-drilled line-up have proved tricky customers for Rangers this season but there was no hope for the Ayrshiremen after goalkeeper Daniel Bachmann was sent off midway through the first half following an off-the-ball clash with Glen Kamara.

Gerrard savaged his team for lacking hunger in the sorry weekend stalemate with St Johnstone that allowed Celtic to take a giant step towards eight-in-a-row.

But there was no sign of that malaise this time as Rangers hunted down their visitors with a ravenous look from kick-off.

They were lucky referee Alan Muir took no action against Joe Worrall just two minutes in as the Englishman appeared to block off Eamonn Brophy in the box.

But with Morelos back in action for the first time since his red card at Aberdeen, Gers once again had a focal point back and it took just seven minutes for them to find it.

James Tavernier measured an inch-perfect ball down the right for Daniel Candeias, whose first-time ball was whipped straight to the unmarked Morelos to tap home at the back post.

Bachmann pulled off a good save from Scott Arfield soon after but that was the Austrian stopper's last involvement as he saw red on 25 minutes.

Former Dundee midfielder Kamara hit the deck claiming he had been struck with an elbow as he and Bachmann waited for a corner delivery. Muir took his time as he consulted his assistants before leaving Bachmann stunned as he reached for his top pocket.

Clarke sacrificed Conor McAleny to put on back-up keeper Jamie MacDonald while there was a further blow as debutant Alex Bruce had to be replaced at the same time after going down injured.

Gerrard's team sensed their chance to put the tie to bed. First Tavernier rattled the underside of the crossbar with a 20-yard rocket – but their second again came from point-blank range on the stroke of half-time.

Candeias threw over another sumptuous delivery, this time from deep in the corner, and Morelos had the easiest header to bring up his quarter-century.
The game was in danger of dwindling down after the break but the introduction of Halliday sent Gers' tempo soaring.

The left-back won possession on half-way, sprayed forward to Ryan Kent before racing on to finish emphatically from 15 yards out on 73 minutes.

Morelos then wrapped up his hat-trick five minutes later as he fizzed the ball past MacDonald at his near post.

And Rangers' top-scorer was not done there, swivelling on the ball before sending a low finish into the bottom corner for number five with seven minutes left.

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