Calum Ferrie saves with a fantastic leap and writes his name in the history books!

Or has he? Calum Scott is checking with VAR... is he on his line?

Cyriel Dessers goes down in the box under pressure from Adam Montgomery.

Calum Scott points to the spot!

Vaclac Cerny drills one into the side-netting from the edge of the box.

Moments later, he drills a shot at goal and Calum Ferrie is there to deny him again. This is heroic goalkeeping performance.

Cyriel Dessers is played in behind and he goes one-on-one... but Calum Ferrie saves!

Perhaps a match-winning moment from the Queen's Park keeper!

Robin Propper's volley at the back post looks destined for the net, but it's blocked again, right off a defender's face.

The fourth official holds up five minutes of added time.

Rangers are once again knocking on the door. James Tavernier's shot is blocked behind off Adam Montgomery's head, and another cross is hoofed clear by Queen's Park.

The nerves are jangling for both sides.

Tom Lawrence is the final Rangers change, replacing Mohamed Diomande. Can he be the man to save Rangers here?

Hamza Igamane and Vaclav Cerny try to work the ball into the box but the cutback comes to Nico Raskin.

"I'm hitting that" thinks the Belgian, but it's high and wide. The groans are getting louder.

Hamza Igamane rattles the ball at goal from outside the box, but Calum Ferrie gets a really strong wrist on the ball. That was swerving away from the keeper.

Rangers work the ball into the box and Cyriel Dessers pulls it back for Ridvan Yilmaz, but it's thwacked over the bar.

Clement tries to encourage his side to hurry it up a bit.

Derek Ferguson
Former Rangers midfielder on BBC Sportsound

It would be unthinkable if Rangers went out the Cup this afternoon and questions would be asked.

It's a big twelve minutes for Phillipe Clement.

Zach Mauchin is down with a bad bout of cramp. Cyriel Dessers is trying to offer him medical treatment but Mauchin wants his own physios to attend to him.

That's one of the longest cramp stoppages I've ever seen.

Unsurprisingly, Rangers are now keeping Queen's Park camped in the visiting box. It's a real siege, but the hosts cannot find a way through.

Every time they need a moment of quality, their touch evades them. It's been really poor in the second half so far.

Adam Montgomery is now on for his Queen's Park debut. The Celtic loanee only joined the club a few days ago.

He's replaced Joshua Scott at left-back, who was down with cramp moments ago. Think we'll see a bit more of that.

This would be the most stunning Scottish Cup upset. Rangers have been much slacker since the break, while Queen's Park have grown in confidence.

They've had one or two chances, and they've taken one quickly while Rangers have wasted multiple opportunities.

Ian McCall
Former Partick Thistle manager on Sportsound

You sensed it might've been coming...

He did exactly the same a minute ago to beat the full-back. Brilliant bit of skill and a great finish!

Mohamed Diomande gives the ball away on the edge of the box and Queen's Park try to fashion a chance. Eventually Seb Drozd gets it in but Zak Rudden's header is blocked behind.

Corner to come.

Queen's Park change as Kyle Hurst is replaced by Seb Drozd.

There was also a shout for handball there, and subsequently a Rangers penalty, but it was quickly waved away.