Celtic suffered their first Premiership defeat in a year thanks to a shock 2-0 loss to St Mirren at Paisley.
Hometown captain Mark O’Hara steered the Saints in front with two minutes remaining in a first half where a very different side to the Hoops were out of form.
Burly Buddies striker Jonah Ayunga, who gave the visiting defense a difficult afternoon, headed the second in the 53rd minute and Ange Postecoglou’s men had no response.
It was a momentous victory for Stephen Robinson’s resilient and well-organised side – St Mirren’s first league win at home to Celtic since March 2010 – and it ended the Hoops’ unbeaten league record which stretched back a year. 1-0 defeat at Livingston on September 19, 2021.
Celtic enter the international break two points clear of league-top Old Firm rivals Rangers and it is perhaps a reminder that there is still a lot of work to be done to retain their title .
After the 1-1 draw with Shakhtar Donetsk in the Champions League on Wednesday night, Postecoglou varied the changes with former Saints player Aaron Mooy, Anthony Ralston, Stephen Welsh, David Turnbull, Daizen Maeda and Liel Abada entering the team, while Scott Tanser replaced Richard Tait for St Mirren.
Celtic supporters chanted ‘if you hate the Royal Family, clap’ during a minute of applause in memory of the Queen before the game and there was a banner held up repeating the same sentiment.
The ball spun end to end early on and, in a hoops attack, a Turnbull header from a Greg Taylor cross flew away.
Celtic had the upper hand with periods of pressure but St Mirren were unintimidated and moved forward sporadically and just before half-time they took the lead with a well-worked goal.
Midfielder Keanu Baccus played against fellow Australian Ryan Strain on the right and his deep cross was headed in by unmarked O’Hara, who had escaped Mooy’s notice.
It was no surprise that Postecoglou made changes at the break, with Portuguese winger Jota and Japanese midfielder Reo Hatate replacing Mooy and Maeda.
Parkhead’s men tried to up the pace but were stunned again when the Saints doubled their lead.
The Celtic defense failed to cope with a long throw-in from Declan Gallagher and striker Curtis Main leaped to head towards goal, with Ayunga nodding from close range.
Postecoglou looked to the bench again and strikers Giorgos Giakoumakis and Sead Haksabanovic replaced Turnbull and Abada.
On the hour mark, St Mirren keeper Trevor Carson recovered a deflected shot from Hatate but at the other end, moments later, O’Hara headed a cross pass past the post from six yards out .
As Celtic increased the pressure, Carson saved a header from Giakoumakis and a drive from Taylor from distance.
Taylor was replaced by Matt O’Riley in the 74th minute as Postecoglou went bust, but the Saints remained diligent defensively as they were keen to inflict a rare league defeat on the champions.