The Bhoys striker became the first player since Henrik Larsson to hit 40 goals in a single season for the club.
If ever there was a time that Celtic were likely to drop points this season, it was on Wednesday night as the already-crowned champions travelled to St. Johnstone for their penultimate game of the campaign.
A fifth title in a row already won, no Scottish Cup final on the horizon, manager Ronny Deila's summer departure already confirmed - in truth, the Bhoys' season is already all but over.
That was reflected in Deila's much-rotated starting XI for the trip to McDiarmid Park last night, and also in the result, as the Hoops lost just a fourth league fixture of the season 2-1.
However, amidst the defeat and the dead-rubber nature of the game, there was one landmark moment as Leigh Griffiths, on his 53rd appearance of the season, scored his 40th goal of the campaign in all competitions.
That strike makes him the first player since Henrik Larsson 12 years ago to reach that figure in a season, with the Swedish legend having surpassed the mark in three of his four final seasons at Parkhead.
Griffiths admitted his pride at having reached the target and emulated Larsson's achievement, and his feat was the primary focus of most Hoops fans on Twitter after the academic defeat.
The majority of supporters hailed the former Wolves man's achievement after he managed just 20 strikes in his first full season at the club last term.
Celtic were always going to drop points today but 40 goals for griffiths is incredible. Your defence is terrified, Griffiths is on fire— Max Codona (@Maxcodona1) May 11, 2016
Great to see Leigh Griffiths get his 40th for the season, fantastic achievement!! @Leighgriff09— Carsano (@Carsonnnn9) May 11, 2016
Griffiths reaching 40 goals this season! In any league that's a remarkable achievement, only going to get better— davidgillespie (@DavidGillespiex) May 11, 2016
Fair play to Leigh Griffiths. 40 goals in a season playing in front of that midfield is incredible. He's been brilliant.— Stevie Jackson (@bobby__peru) May 11, 2016
Would never have thought when he signed that Griffiths would score 40 in a season, proved everyone wrong on yersel ma man— Ryan Howard (@14RyanHoward) May 11, 2016
Doesn't matter if we're champions.. I hate loosing but well done Leigh Griffiths on reaching 40 goals— SteKelly (@stekelly89) May 11, 2016
There was a time I would have sold Griffiths to be honest, put his head down and worked hard, he's undoubtedly our biggest player now!— KevinMcAneney67 (@83Ways2SkinACat) May 11, 2016
Delighted for Leigh Griffiths 40 goals for the season unbelievable achievement— Stephen Devoy (@DevoyStephen) May 11, 2016
However, for some Griffiths' achievement was just papering over the cracks, whether those cracks be simply a bad result or what has been something of a disappointing season by Celtic's standards despite the title win.
Buzzing for Griffiths - raging that we can't actually beat St Johnstone— Hayley McGuire (@haylzmcg) May 11, 2016
Griffiths will be attracting some interest I reckon after hitting 40 goals.— Duncan (@DMacphaidin) May 11, 2016
This is the downside to his goals.
Positives from Celtic tonight? Griffiths 40th goal and...........................nil— Andy Murdoch (@AGM60) May 11, 2016
Honestly dread to think where we would be without Leigh Griffiths probably 4th in the league— Boltonbhoy (@scott_melville) May 11, 2016
Then there was this poor chap, looking ahead to an inevitable spiral of despair.
Griffiths will be gone in the summer— Henke (@GlasgowsGreen) May 11, 2016
The new manager will be underwhelming
We won't qualify for the Champs League