There are days when fans have a harder shift than players. No question asked of Celtic by St Mirren was more taxing than the thought both sets of fans had to devote to whether or not to turn up and watch i.

Celtic beating St Mirren - top versus bottom - was as inevitable as the sun rising in the morning.

Celtic dismantled managerless St Mirren easily enough but another thin, sparse crowd turned up to watch it.

Comically, an attendance was reported as 44,827.It looked around 25,000 at most.

Some regulars maybe preferred Manchester United-Liverpool on television, or didn't fancy the weather, or were under an obligation to spend their Sunday some other way, but the end result was a frieze of green-and-white seats as Celtic went about the formality of delivering their eighth consecutive win in the Premiership.

Scott Brown scored twice and James Forrest and Anthony Stokes once. They created a barrowful of other chances.

Substitute Stefan Scepovic mucking up three of them was hardly news, but it was interesting that John Guidetti could not help himself to one.

He should have had one in the second half but lashed a shot at Mark Ridgers from point-blank range.

Otherwise he was less of a force than he might have been a month or two ago, when opponents had yet to wake up to his threat.

Guidetti has scored only two in his last six appearances and none in his last three.

That's a drought by the high standards he set for himself and he reacted petulantly at half-time, hauling off his shirt and throwing it into the crowd.

If boredom kept many Celtic supporters away, fear would have been the disincentive for St Mirren's followers.

Only the truly hard core turned up, to their credit. Bookmakers had St Mirren as long as 22/1 to win and no-one in control of their faculties was tempted by that.

A defeat would have been inevitable had Tommy Craig still been in charge and it was just as sure without him.

Gary Teale and David Longwell, in charge on an interim basis, were charged with avoiding a car crash and a cricket score.

They managed that, but it was looking dicey when they had shipped three goals in the first 18 minutes.

St Mirren worked three great chances for themselves in the first 20 minutes yet were 3-1 down by then.

The defensive slackness Celtic show, which gets punished in Europe, was not exploited by St Mirren.

Barely seconds into the game John McGinn dispossessed Forrest and played the ball across the box to the unmarked Kenny McLean, who made a total mess of it.

Then McGinn repeated the trick by beating Virgil van Dijk to square the ball for McLean. He "scored" this time, but was offside.

They got their goal when McLean's free-kick was nodded into the goalmouth by Mark McAusland's header and hooked into the net by Sean Kelly or St Mirren's first goal at Parkhead in five years. Poor Celtic defending helped.

That had given St Mirren a foothold in the game at 1-1 but things soon accelerated away from them.

The rest of the afternoon became an uninterrupted sequence of Celtic chances and surprisingly few of them were converted.

Ridgers made a handful of important saves but Celtic's finishing lacked conviction and quality and undid some of the fluid passing and movement which opened up St Mirren time and time again.

Manager Ronny Deila liked most of what he saw and was entitled to his post-match verdict that they could have had ten.

Brown and Forrest had been rested against Dinamo Zagreb in midweek and both made scoring returns.

A midfielder who can weigh in with goals is hugely valuable to any side and Brown - never a consistent goalscorer in his career - delivered a couple.

When Anthony Stokes's delivery was touched on by Guidetti it found Brown in space to fire a drive into the corner for the opener.

Not getting a goal may mean Guidetti felt he had a bad game, but he helped make Celtic's first couple.

It was his perfect lay-off which played Forrest through to place a low shot across goal and inside the far post and put them ahead.

Forrest made the third goal by squaring the ball for Brown.

The wee winger's departure at half-time was a pity given the spark and invention he had shown in the opening 45 minutes.

He was replaced by Callum McGregor while Guidetti took a knock in the second half and was replaced by Scepovic, whose first touch was a superb volley which almost scored.

That was an untypical moment of excitement around the Serb and it looked far more familiar when he had two one-on-one chances later in the game and made a mess of both of them.

Somehow he hit the inside of the post with another effort and that didn't go over the line either.

Stokes had a shot saved, another effort disallowed for offside and a free-kick just wide.

Guidetti's big chance was saved and Stefan Johansen's finishing let him down.

St Mirren could hardly have believed they were still holding on to respectability although Stokes increased the lead by getting the ball under control at his feet and tucking away a fourth in the 67th minute.

St Mirren's little victory was in resisting Celtic for almost 50 minutes between the third and fourth goals.