Buddies left shell-shocked as Celts trim the gap to leaders Hearts to four points

If Celtic somehow emerge from this internecine conflict with the Premiership trophy still under lock and key then Martin O'Neill might be obliged to make a return trip to Glasgow to take a bow come May.

The fact that a club which is tearing itself apart off the field is still in contention to retain the main domestic prize owes a great deal to the 73-year-old's willingness to accede to a request from Dermot Desmond which he might well have declined.

Since Brendan Rodgers departed the scene in the wake of a pitiful display at Tynecastle last month, O'Neill's presence has ensured a drama hasn't turned into a full-blown crisis.

On the back of comprehensive wins over Falkirk and Kilmarnock, this hard-fought and dramatic win over St Mirren ensured the side hasn't missed a beat in the league since the Northern Irishman returned in an interim capacity.

Ahead of Hearts' trip to Pittodrie, Celtic are only four points off the pace in the Premiership. At the point where Rodgers departed, they were nine adrift.

O'Neill is likely to still be in charge at Easter Road on Sunday, but he'll surely be well gone by the time the campaign goes down the home straight.

Callum McGregor unleashes an unstoppable stoppage-time winner for Celtic

The Celtic skipper celebrates his dramatic late clincher in Paisley

Interim boss Martin O'Neill secured a third successive Premiership victory

His steadying influence in these trying times won't be soon forgotten, however.

Nor will Callum McGregor's astonishing strike deep into injury time which settled this match.

The ongoing unrest in the stands which culminated in a chaotic annual general meeting on Friday would have made for a difficult enough backdrop.

O'Neill's also had to contend with a debilitating injury list which has deprived him of players of the ilk of Cameron Carter-Vickers, Alistair Johnston, Callum Osmand, Jota, James Forrest, Kelechi Iheanacho and Marcelo Saracchi.

Bits of the machinery have been hanging off. Somehow, the veteran has ensured Celtic have still moved forward.

If he is to be unveiled as the next Celtic manager in the coming weeks, Wilfried Nancy will owe O'Neill a huge debt of gratitude.

With only two wins in five away games prior to arriving in Paisley, this assignment had danger written all over it. At the end of a difficult few days, it felt like a big win.

Notwithstanding a great performance in the League Cup semi-final against Motherwell, St Mirren's league form will be giving boss Stephen Robinson concern.

Buddies boss Stephen Robinson would have felt hard done by to lose in such agonising fashion

This loss leaves the Buddies with just one point from their last six matches. If they are to challenge for the top-six for the fourth successive season, they'll need to turn this around quickly.

There's so much noise swirling around Celtic Park these days that it feels like a blessed relief whenever a football match actually takes place.

Predictably, this one only got underway after those in the visiting end brandished red cards and chanted against the board -- a repeat of the scenes in the Kerrydale Suite the previous day.

Despite a lengthy injury list, every member of O'Neill's starting side was a full international.

Three weeks before meeting at Hampden in the Premier Sports Cup final, this was a chance for both teams to put down a marker.

It was a full-throttle start from Saints. Their pace, power and desire pegged Celtic back.

Declan John's low cross from the left saw Conor McMenamin fly in at full stretch. Kasper Schmeichel was relieved that no connection was made.

Seb Tounekti was the first man to threaten for visitors when he gathered McGregor's pass and went for goal from the left side of the box. The wide man will feel he ought to have hit the target.

Daizen Maeda saw a promising effort blocked in the second half

Robinson's side were smart in their use of the ball and organised when they didn't have it. Celtic had to strive for any openings which came their way. They didn't enjoy any prolonged periods of pressure.

Miguel Freckleton's surge up the flank won a corner. McMenamin waited outside the box for the ball to find him. A fierce left-strike looked net-bound all the way until it flashed just wide of the post.

Johnny Kenny was starved of any meaningful service. When Reo Hatate did pick him out, his technique let him down and the ball landed harmlessly in the stand.

It rather summed up Celtic's efforts in the opening half. Pedestrian and passive, O'Neill would have some harsh words to impart.

The only criticism you could make of Saints was that they didn't threaten enough in the final third. Freckleton should have made more of a half chance which fell to him when Mikael Mandron's initial shot was blocked by a defender. Schmeichel remained untroubled.

With Luke McCowan replacing Kenny at the break and Daizen Maeda now through the middle, the was a bit more life to the visitors. Marcus Fraser did well to get in the way of Kieran Tierney's strike.

St Mirren's energy levels and commitment to pressing were remarkable. Whenever a visiting player had a yard of space, an opponent seemed to appear in a puff of smoke.

The marginal improvement in O'Neill's side came without them ever controlling the contest.

Celtic players take the acclaim of their fans after a dramatic victory on the road

McGregor's shot did strike Killian Phillips on the arm in the box, but the ball hadn't travelled far enough for it to be a penalty.

Keanu Baccus' attempt to deceive Schmeichel with a curling strike didn't have enough whip on it.

O'Neill introduced Hyun-jun Yang for Tounekti. There was more energy in the side, just not a great deal of quality.

Scales scooped the ball into his own net after Celtic made pig's ear of clearing a free-kick. The offside flag for McMenamin was backed up by VAR.

Twice Yang went close only for a St Mirren defender to go to ground and block the effort.

Increasingly desperate, O'Neill also threw on Benjamin Nygren and Dane Murray.

Maeda darted away from Alex Gogic and had his ankles clipped just outside the box. Arne Engels fired the free-kick into the wall.

Celtic showed more in the final 20 minutes urgency, but the best chance of the 90 fell to McMenamin at the other end. His shot was tame and straight at the keeper.

McMenamin went close in the early stages of a tense affair for St Mirren

Maeda thought he'd won it when he got goal-side of Freckleton. The defender pulled off an outstanding recovery tackle.

Just when you thought this was going to be a costly night for Celtic, though, McGregor struck.

The four minutes of allotted injury time had already come and gone when he picked the ball up 35 yards out and drove at goal.

What he unleashed was a missile from 25 yards which Shamal George didn't even get close to as it flew into the top corner.

O'Neill jumped about on the touchline in trademark style. It was the perfect ending to a difficult few days for the Parkhead club.

ST MIRREN 0 CELTIC 1: Captain marvel McGregor has the final say