St Mirren were beaten 4-0 by league leaders Celtic at Celtic Park.
Liel Abada and Kyogo Furuhashi goals had the hosts 2-0 up at the interval with Kyogo adding a third in the second-half before a late David Turnbull strike rounded off the match.
Manager Stephen Robinson made four changes to the side that lost narrowly at Tynecastle on Friday. Charles Dunne and Ethan Erhahon returned from suspension, while Ryan Strain and Jonah Ayunga also came into the starting 11. Richard Taylor, Mark O'Hara, Ryan Flynn and Alex Greive dropped out.
It was Saints who had the ball in the net first when Curtis Main found his way on to an Alex Gogic header to flick beyond Joe Hart, but the linesman's flag was raised. A VAR check confirmed the forward was marginally offside.
Celtic took the lead on 15 minutes when Abada opened the scoring. A corner from the right was met by the head of Carl Starfelt whose header was beaten away by Saints goalkeeper Trevor Carson. It landed at Yuki Kobayashi's feet and he then cracked the post before it was eventually smashed home by Abada.
The Buddies reacted well to going behind and almost drew level just two minutes later but for a wonderful save from ex-England international Joe Hart. Jonah Ayunga - making his first start of 2023 - drove inside from the right and fired towards the far corner only for the Celtic goalkeeper to get a hand on it to push behind. Ayunga was then gifted the ball by Starfelt a few minutes later but had his effort from 20 yards blocked by Kobayashi.
Celtic doubled their lead on 35 minutes when Kyogo broke the offside trap to meet a pass from Reo Hatate and the Japanese forward lifted the ball over Carson to make it 2-0. It was subject to a quick VAR check to determine whether the striker had been offside but the goal stood. The hosts could have added a third moments later when a ball from the right was almost turned home at the back post by Jota, but he somehow knocked wide from just a few yards out with Saints two behind going into half-time.
The hosts added a third eight minutes after the restart when Kyogo got in between the Saints defence to meet a low cross from Matt O'Riley and knocked beyond Carson. It was initially flagged as offside but a VAR check saw the goal given.
Stephen Robinson made a triple substitution just after the hour mark with Richard Taylor, Greg Kiltie and Alex Greive replacing Charles Dunne, Keanu Baccus and Jonah Ayunga.
Declan Gallagher wasn't far away from pulling a goal back on 65 minutes when he rose highest to meet a Strain cross but his header came off the cross bar and went over with Hart at full-stretch.
Celtic thought they had made it 4-0 with a little over 15 minutes remaining when Kyogo charged forward and laid it on a plate for substitute James Forrest to knock home from just a few yards. The offside flag was raised and VAR confirmed it was indeed offside.
The hosts would add a fourth with substitute David Turnbull firing home from 25 yards in the final few minutes to round off the game for Celtic. Saints did almost grab a consolation a minute later, but Gogic's volley was well clawed away by Hart.
Attention now turns to the Scottish Cup with Saints hosting Dundee at the SMiSA Stadium on Saturday.
Full-Time: Celtic 4-0 St Mirren
St Mirren: Carson, Gallagher, Shaughnessy (c), Dunne (R.Taylor 61), Strain (Flynn 84), Baccus (Kiltie 61), Erhahon, Gogic, Tanser, Ayunga (Greive 61), Main
Subs Not Used: Urminsky, Kenny, F.Taylor, Olusanya, Brophy
Celtic: Hart, Johnston, Kobayashi, Starfelt, Juranovic, O'Riley (Turnbull 70), McGregor (c), Hatate (Mooy 70), Abada (Forrest 70), Jota (Haksabanovic 79), Kyogo (Maeda 79)
Subs Not Used: Bain, Welsh, Ralston, Iwata
Referee: Steven McLean
Assistant Referee: Calum Spence
Assistant Referee: Graham McNeillie
Fourth Official: Iain Snedden
VAR: Andrew Dallas
Assistant VAR: Sean Carr
