Ross County have improved in this second half and look the more likely to score. The earlier header wide by Alex Samuel was followed by another from Kayne Ramsay and it's going to be a nervous 10 minutes or so for Livi.

Image source, SNS

Motherwell are starting to look frustrated as the scoreline continues to stay level as they heard towards extra-time.

No real chances of note for either team, with Morton defending fearlessly.

Nadir Ciftci, you lucky, lucky boy.

Replays show the St Johnstone striker has deliberately tried to stamp on his marker's toes with the ball beyond him.

If any official sees that, he's off.

It's all Dundee now, but they'll want a second goal to kill this tie off.

Cammy Kerr has just headed a good chance wide.

St Johnstone are putting the pressure on but they need more cutting edge.

Jamie McCart bends one into the box and Nadir Ciftci is there, but his cushioned volley is off target.

Nervy few moments in the penalty box for Dundee United.

From the corner kick, Ash Taylor gets to it and bullets a header at goal and it's cleared off the line by Nicky Clark.

Rory McKenzie should also do better when presented with a chance, but doesn't get enough power behind it and Ben Siegrist makes the save.

Aberdeen's Lewis Ferguson hits a free kick from almost 30 yards out and it smashes off the bar!

Kevin van Veen, who has just replaced Kaiyne Woolery, dances between defenders on the edge of the box before his shot stings the palms of Morton goalie Jack Hamilton.

Jacob Butterfield, who went close at the start of the second half, isn't far away again.

The St Johnstone midfielder rifles a left-foot strike towards the top-right corner, but it's narrowly off target.

On-loan Wolves midfielder Connor Ronan goes close to adding to St Mirren's lead but is thwarted by a good stop from goalkeeper. Aidan McAdam.

Almost a second for Livingston as Odin Bailey collects outside the box, finds some space and fires narrowly wide.

Still no way through for the Championship visitors as Frankie Musonda heads against the post.

Decent effort from Saints captain Liam Gordon, who makes a yard for himself and drills one low from 20 yards.

Drags wide of the far corner, though.

Kyle Lafferty makes an appearance from the Kilmarnock bench. Can the returning striker make the difference with this tie finely poised?

Moments after his introduction Kilmarnock do have a chance, but Oli Shaw heads into the hands of Benjamin Siegrist from close range.

The Red Lichties go close to doubling their lead but Colin Hamilton's well struck shot is tipped wide.