Finally...

He's having a long look at this...

Steven McLean has his hand to his ear and he's off to check the monitor...

How's that not gone in?

Liel Abada gathers a cross at the back post, dummies Trevor Carson then smashes towards goal.

It's blocked on the line. But is it a handball? I think we're in for a lengthy VAR check...

Double change for St Mirren as Stephen Robinson rolls the dice.

Greg Kiltie is on for Keanu Baccus in an attacking switch. The other switch sees Scott Tanser make way for Thierry Small.

Now then, a deep set-piece for St Mirren. What can they create?

Scott Tanser's delivery pops about in the box before Tony Watt eventually gets a head on it.

The effort is simple for Joe Hart to gather.

Kheredine Idessane
BBC Sport Scotland at Celtic Park

Daizen Maeda's time as central striker is up as he switches out to the left to accommodate Oh, who's had a couple of cameo appearances so far in Scotland and will now get around half an hour to impress.

Reo Hatate and Matt O'Riley will look to energise the Celtic midfield which hasn't quite fired on all cylinders this evening.

Daizen Maeda is off down the left again and crosses to the back post.

Liel Abada leaps for it but his header is way off target in the end.

I may be reading into those subs too much but I have a feeling Ange Postecoglou might not be too happy with his side.

Triple change for Celtic.

Off go Aaron Mooy, Jota and David Turnbull. On come Reo Hatate, Matt O'Riley and Oh Hyeon-gyu.

St Mirren posing a bit more of a threat now.

Tony Watt makes a yard from himself in the box before seeing his drive blocked.

St Mirren look to get some joy with a ball into the box as Declan Gallagher gets his head on it.

The centre-back is offside, however.

Alistair Johnston has been excellent this second half.

St Mirren are having to deal with cross after cross from the Canadian. The standard of delivery is top notch.

Kheredine Idessane
BBC Sport Scotland at Celtic Park

Celtic are looking rather more sprightly at the start of this second half.

Were a few things said in the dressing room by Ange Postecoglou? He'd have been happy with the half-time scoreline but I wonder to what extent he was satisfied with the overall performance?

St Mirren are hanging on.

Again another fine ball in from Alistair Johnston. It seems to just hit Marcus Fraser before bouncing off his own post.

Celtic look to have clicked back into gear early this second half as Declan Gallagher has to cut out a dangerous Aaron Mooy cross.

The resulting corner comes to nothing, however.

What a ball, Alistair Johnston.

A low ball from the right carves open the St Mirren defence and Daizen Maeda slides in for his second but he just doesn't get there.

We go again...

The second half is fast approaching. This is the goal that splits the sides.

Image source, SNS

Image source, SNS

Image source, SNS

Inverness CT manager Billy Dodds tells BBC Sportsound: "It's the best performance since I've been here. We've had some big results but performance wise, looking dangerous and solid in shape, helping one another out, being ruthless in front of goal. It was all there today.

"It's the first time I've been able to sit there and not bite my fingernails. It was nice, we were decent and deserved to go through.

"I asked them to take the final step at half-time. Take one goal, you'll spook them, and Billy has come up with two belters. Billy is more than a goalscorer. I want him to enjoy the last few years of his career and he did that today."

Image source, SNS