Celtic's most decorated player of all time, James Forrest, scored for a record-breaking 16th consecutive season in stoppage-time to make sure trophy day did not fall flat against a St Mirren who fell just short of European qualification.

With nearly the last kick of the ball, the veteran winger fired low past goalkeeper Zach Hemming to deny St Mirren a famous victory.

Jonah Ayunga's strike looked as if it would fire the Paisley side to only their second victory at Celtic Park in 38 visits.

It also looked as if it would seal a Conference League place, with St Mirren needing to better the result of a Dundee United side who trailed against Aberdeen.

However, United came from behind to lead before Forrest scored at the death deny Stephen Robinson's side the victory that their composed, disciplined performance seemed set to earn.

St Mirren's organisation and work-rate frustrated Celtic for most of the first half and, when their chance came, Ayunga fired hard and low into the bottom left-hand corner of the net when the home defence failed to clear a free-kick.

As if to underline the lack of intensity and quality from Celtic, Hemming was largely untroubled throughout, but was a relieved spectator when Daizen Maeda headed wildly over from substitute Forrest's fine cross.

It was not until the final few minutes when Hemming was called into action to deny late attempts from Johnny Kenny and Yang Hyun-Jun.

Forrest, Yang and Luke McCowan all came on for the last half hour for Celtic and, while the champions did improve slightly, St Mirren held firm with some terrific last-ditch defending necessary and also some composed play on the break.

Even had they won, they would not have been able to improve on sixth place thanks to United's win over Aberdeen.

For Celtic, how fitting that a modern-day great got the record-breaking goal before bringing the trophy out for their 13th title party in 14 years.

Ninety-two points and 112 goals tells you all you need to know about Celtic's season.

That there were still howls of derision from the home fans on trophy day when their heroes huffed and puffed but failed to blow the St Mirren house down speaks volumes of the standards expected at Parkhead these days.

Manager Brendan Rodgers will not be happy that the party was spoiled somewhat by the performance.

The silver lining for him will be that his men will go into next week's Scottish Cup final, with a treble on the line, fully aware that they canot let their levels drop again if they want to complete the domestic clean sweep.

Too many of his usual high performers could not find their usual standards. Perhaps understandable, given this title was effectively won a long, long time ago.

Absolute heart-break for St Mirren. They did their bit, with a fabulous performance and draw at the home of the chamions.

That it still was not enough to secure them fifth place - and European football in successive season for the first time - will be a bitter pill to swallow after nine points from 15 post-split.

Regardless of that disappointment, it has been another terrific season and the pain will eventually dissipate as they reflect on yet another top-six finish and a sparkling end to the campaign.

Anyone watching St Mirren this season will surely have been impressed by their organisation, work ethic and quality.

Solid at the back, inventive in midfield and pacy out wide, it is no surprise they have had another good season once they recovered from their European exertions.

Celtic manager Brendan Rodgers: "We enjoy this today and tonight and the supporters deserve to do that, but you are quickly on to next week and the next season.

"A lot of guys have had minutes now and now we can form the plan for the Scottish Cup final. It's been a wonderful season up until now and we can make it a really memorable one next weekend, but we have a lot of hard work and preparation before then."

St Mirren manager Stephen Robinson: "Even if we had won the game, we couldn't have got Europe, but to remain unbeaten in the top six and come here and not be beat by a Celtic side coming to party.

"In the first half, I'm not sure they had a shot on target - we were really disciplined. You obviously don't get so much of the ball against Celtic, but when we did, we tried to play, we tried to pass and we got punished for our one mistake right at the end.

"Overall, I can't ask any more of this group of players. They are playing way above the resources that we are putting into the team and I am proud to say I am the manager of this group of boys."