Kenny Crawford
BBC Sport Scotland at Somerset Park

Ayr largely controlled the opening 15 minutes but Clyde are creeping back into this match.

Debutant Bully Wee goalkeeper Connor Quinn got some much needed early confidence by pushing Gary Harkins' low effort from 10 yards round the post.

Since then the 18-year-old hasn't been majorly tested though and Clyde have had a few set pieces that have kept the Honest Men honest.

Better from Saints.  Marauding right-back Richard Foster has a cross-cum-shot deflected into the side-netting.  After the subsequent corner, Danny Swanson sends a snap-shot from the edge of the area narrowly wide of the left-hand post.  

Dundee are denied a leveller by Killie keeper Freddie Woodman. Former Rugby Park man Mark O’Hara breaks away from the home defence but the advancing Killie goalkeeper stops his angled effort with his legs.

Some desperate defending by Dunfermline saves the day as Danny Redmond breaks into the home penalty box and passes low into a crowded and muddy penalty box. The chance created by a fine through ball from new signing Giannis Skondras.

Chris Duggan heads wide from just a few yards. A glorious chance for the home side...

Another sniff for Kilmarnock striker Kris Boyd. The lively Jordan Jones curls a lovely ball into the box, but the unmarked striker cannot divert his header on target from a few yards out.

Kenny McLean nods wide from a lovely, floated Jonny Hayes cross from the left. It was a superb delivery, but McLean glanced wide at full stretch. Aberdeen very much in the ascendancy.

Niall McGinn tees himself up for a sumptuous dipping volley from outside the County box. It swerves and drops under the crossbar, but Scott Fox leaps high to tip it over. Brilliant effort from the Dons forward.

Eamonn Brophy warms the fingers of Sean Murdoch with a fine drive that Dunfermline goalkeeper Sean Murdoch beats away for a corner at his front post.

Accies apply the early pressure and, after a poor clearance, Darian MacKinnon fires a drive a feet wide of the Pars post.

Ayr are first threaten as Gary Harkins sends a drive just wide of new Clyde goalkeeper Connor Quinn's post.

A lively start in Dingwall as Alex Schalk has the ball in the net for the hosts - it's swiftly, and correctly, ruled out with the striker offside.

And we're off. Who's going through to join Celtic in the last eight of the Scottish Cup?

Kenny Crawford
BBC Sport Scotland at Somerset Park

Two teams who have been stuttering in their respective leagues of late, looking to extend their stay in the Scottish Cup and secure a precious quarter final place.

October was when Ayr United last won a match here at home and the only victories since then have been in the Scottish Cup - away to Brechin and away to Queen's Park.

Clyde's two wins in their last 10 matches have also been in the cup - beating Arbroath and Stirling Albion to set up this tie.

Could be a big day for young Clyde goalkeeper Connor Quinn, signed by Barry Ferguson during the week as a last minute stand-in for the suspended John Gibson.

Inverness CT manager Richie Foran: "Outclassed, simple as that. Six-nil is a tough one.

"We went and had a go at the start and that's all I could ask from the lads.

"This is one of the best Celtic teams assembled in a good few years. They've got confidence running through their veins. There was no stopping them today."

Image source, SNS

St Johnstone are the ones with the cup pedigree as they entertain Partick Thistle.

The Perth side have been to eight major semi-finals in the past 10 seasons, winning the Scottish Cup in 2014, while the Glasgow outfit have not been to a major final since beating Celtic in the League Cup in 1971. 

Indeed, Thistle have not reached the Scottish Cup quarter-finals for nine years and lost the last time they met Saints in the competition - 2-0 at McDiarmid Park six years ago almost to the day.

However, the Jags won 2-1 on their last visit to Perth in October, although St Johnstone gained revenge for that with a 1-0 win at the start of this month at Firhill - the latest of four meetings between the sides won by the away team.