FT: Celtic 5-1 St Mirren - Daizen Maeda steers in early on; Reo Hatate slots home from spot with Ben Taylor dismissed for the handball; Oh Hyeon-gyu nets first Celtic strike
Mark O'Hara scores from the spot for visitors Greg Kiltie is brought down only for Matt O'Riley & Hatate to counter
AET: Ayr 4-1 Elgin - Kane Hester puts underdogs ahead before Fraser Bryden levels at the death; Ben Dempsey & Dipo Akinyemi (2) score in ET
FT: Dundee Utd 0-1 Kilmarnock - Kyle Vassell nods in from Danny Armstrong corner; Loick Ayina sent off late on for hosts on debut
FT: Livingston 0-3 Inverness CT - Billy McKay gives Championship club advantage before Sean Welsh makes it two; McKay nets third
FT: Raith Rovers 3-1 Motherwell - Jamie Gullan & Sam Stanton score; Kevin van Veen lashes in scrappy effort before Ismael Goncalves scores on debut
Celtic 1-0 St Mirren
Cameron Carter-Vickers, what a block!
Alex Greive turns Carl Starfelt in the Celtic box. The St Mirren striker's shot looks certain to burst the net but Carter-Vickers gets in the way.
A reminder St Mirren very much remain well in this tie.
Daizen Maeda
He meant that one!
Liel Abada, just on the pitch, slips Aaron Mooy down the right and the Australian's ball across the face of goal is slid in by Daizen Maeda.
Image source, BBC Sport
Celtic 0-0 St Mirren
Oh no. Kyogo is down getting treatment after coming between a tackle from Marcus Fraser and Keanu Baccus.
He's holding that shoulder that gave him a bit of bother last season and he'll have to come off.
On comes Liel Abada. Big blow for Celtic.
Celtic 0-0 St Mirren
Just got a couple replays. 100% a cross.
Celtic 0-0 St Mirren
Daizen Maeda races down the left and his looping effort bounces off the far post before St Mirren clear.
Was it a cross or a shot? Who knows.
Celtic 0-0 St Mirren
Carl Starfelt needs to be alert to clear a dangerous Scott Tanser cross.
If the Swedish centre-back failed to get there, Curtis Main had a tap-in.
Celtic 0-0 Saint Mirren
Kheredine Idessane
BBC Sport Scotland at Celtic Park
In the first few minutes, there's already a pattern of play emerging.
Saints have hit a couple of long diagonal balls into Alistair Johnston's area of the pitch, inviting Curtis Main to go head to head with the Canada right-back. Could be an interesting duel, with Cameron Carter-Vickers also around to lend a defensive hand if need be on that side.
Celtic 0-0 St Mirren
Kheredine Idessane
BBC Sport Scotland at Celtic Park
Smoke billows from the corner of the ground housing the St Mirren support, who've brought a few pyrotechnics with them this evening. It's like a Glasgow east end fog.
Through the haze, you could still see the silky skills of Jota helping him nip past a couple of St Mirren players and draw a fine early save from Trevor Carson in the Saints goal.
Celtic 0-0 St Mirren
St Mirren getting a bit of a breather as Celtic knock the ball about the back.
Celtic 0-0 St Mirren
First save for Trevor Carson.
Jota charges to the edge of the area and smashes one but the St Mirren keeper palms round the post.
Celtic 0-0 St Mirren
Celtic are trying to fly out the traps as they usually do but St Mirren are doing a good job of smothering them so far.
Celtic 0-0 St Mirren
And we're off. This is your place for your Saturday night entertainment this evening.
Don't worry, you'll get The Masked Singer on catch-up.
Celtic v St Mirren (17:30)
The disco lights are flashing. The tunes are pumping. The players are out the tunnel.
Ayr get through comfortably in the end.
They trailed to Kane Hester's first-half goal but Fraser Bryden's 90th-minute leveller and Ben Dempsey's extra-time penalty turned the tie in the hosts' favour.
Dipo Akinyemi added another two for the Honest Men to ensure progress.
Image source, SNSDipo Akinyemi scored in the 103rd and 106th minutes
Celtic v St Mirren (17:30)
Kheredine Idessane
BBC Sport Scotland at Celtic Park
Plenty of noise from the wedge of St Mirren fans to the right of the main stand at Celtic Park, who're hoping to follow Inverness and Raith Rovers into the quarter-finals by producing another Scottish Cup shock.
There are still a few empty seats in the home section, which isn't quite sold out.
The Buddies' task will be to try to keep them as quiet as possible for as long as possible. No mean feat, given the barrage of goals here so far this season.
Celtic v St Mirren (17:30)
Image source, SNS
Image source, SNSCeltic v St Mirren (17:30)
Kheredine Idessane
BBC Sport Scotland at Celtic Park
St Mirren are also the last Scottish side to win at Celtic Park, although you have to go back a couple of years for that.
Not as far back as the last time they knocked Celtic out of the Scottish Cup on their home patch, though, that's nearly 100 years ago - 1930 to be precise.
Celtic v St Mirren (17:30)
The only Scottish team to beat Celtic this season? St Mirren.
Stephen Robinson's men will need a repeat of their September performance if they stand a chance of progression.
Even then, it might not be enough. That win came in Paisley. It's a different story at Celtic Park, where tonight's hosts have a 100% win record domestically this term.
Image source, SNSSt Mirren consigned Celtic to their only 2022-23 domestic defeat so far in September
I can confirm Mr Postecoglou has been cut free and will be in the home dugout this evening.
Allow Twitter content?
This article contains content provided by Twitter. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read Twitter’s cookie policy, external and privacy policy, external before accepting. To view this content choose ‘accept and continue’.
Celtic v St Mirren (17:30)
St Mirren boss Stephen Robinson tells BBC Sportsound: "We've beaten [Celtic] once before this season. It's a different game here.
"We've got a good group of boys who believe in each other. We've worked on certain areas we feel we can control but we need to be at the very top of our game.
"We won't go into the game with any fear."