St Mirren exited the Scottish Cup with defeat at Celtic Park, but the 5-1 scoreline was harsh on Saints who - for 75 minutes - competed well with Celtic until a red card for Richard Taylor.
Taylor was one of two changes made by manager Stephen Robinson as he replaced Charles Dunne who dropped out with a hamstring injury. Declan Gallagher came in for Greg Kiltie in the other change from last weekend's 1-0 loss to Hibernian.
Trevor Carson was called into action early on with the Saints stopper making a strong two-handed save to push away Jota's effort on two minutes after the Portuguese winger has jinked his way into the St Mirren box.
Saints looked to hit Celtic on the counter on a couple of occasions early on, but it was Celtic who came closest to the opener in the first 10 minutes when Daizen Maeda's attempted cross sailed over the head of Carson, but came back off the post.
The home side were forced into an early change when Kyogo was came off with an injury to be replaced by Liel Abada. That saw Maeda moved to centre-forward and that shift of position would pay dividends for the the hosts as the Japanese forward put them ahead on 16 minutes. Maeda was on hand just six yards from goal to slide home from Aaron Mooy's low ball across the face of the box.
Saints almost levelled just two minutes later when Greive did well to turn Carl Starfelt in the box and his effort looked like it was heading for the far corner of the net, only for Cameron Carter-Vickers to head clear the danger. Carter-Vickers was the man alert again for the hosts on 33 minutes when his vital interception denied Greive the chance to go one-on-one with Joe Hart in the Celtic goal.
St Mirren were also forced into a change a few minutes before half-time when Greive couldn't continue after going down with an ankle injury. He was replaced by Tony Watt. Alex Gogic had a go from 20 yards in the final minutes of the half, but his effort flew over while Celtic had a big chance for a second before the interval only for Jota to flick Mooy's cross over.
Celtic almost grabbed a second six minutes into the second-half when a low Alastair Johnston ball across from the right came off Marcus Fraser and crashed off the post before Saints managed to clear.
Saints were making it difficult for Celtic and almost had a big opportunity to level just after the hour mark when Keanu Baccus broke forward and slipped in Watt down the left-side. The forward cut into the box but had his shot blocked.
The game completely changed with 15 minutes remaining when Saints were reduced to 10 men and Celtic were awarded a penalty following a lengthy VAR check. Taylor was shown a red card for a handball in the box and Reo Hatate stepped up to score from 12 yards.
Celtic added a third five minutes later when substitute Oh scored from close-range. Carson had initially saved Callum McGregor's effort but the ball fell to Oh who knocked home from just a few yards out.
Saints didn't give up and pulled a goal back on 87 minutes from the penalty spot. Greg Kiltie was fouled by Carl Starfelt and O'Hara slammed home from the spot. But Celtic would add to the scoring with Matt O'Riley and Hatate scoring stunning efforts in the final few minutes to put a harsh reflection on the final scoreline.
Mark O'Hara pulled a goal back for Saints from the penalty spot (Image: Allan Picken)
Full-Time: Celtic 5-1 St Mirren
St Mirren: Carson, Fraser, Gallagher, R.Taylor, Strain (Flynn 77), Baccus (Kiltie 71), O'Hara (c), Gogic, Tanser (Small 71), Greive (Watt 41), Main (Shaughnessy 77)
Subs Not Used: Urminsky, Kenny, Offord, Jamieson
Celtic: Hart, Johnston, Starfelt, Carter-Vickers, Taylor, Mooy (Hatate 63), McGregor (c), Turnbull (O'Riley 63), Jota (Oh 63), Kyogo (Abada 14), Maeda (Haksabanovic 78)
Subs Not Used: Bain, Kobayashi, Iwata, Forrest
Referee: Steven McLean
Assistant Referee: Douglas Ross
Assistant Referee: Alastair Mather
Fourth Official: Graham Grainger
VAR: Colin Steven
Assistant VAR: Gary Hilland
