Scottish Premiership kings Celtic suffered a surprise defeat against Livingston, going down 2-0 at Almondvale Stadium.
The game saw the Hoops reduced to ten men on 26 minutes when Ryan Christie was shown a straight red card for a wild tackle on Scott Robinson.
And the hosts made the most of their man advantage with Robinson and Lyndon Dykes giving them the famous win.
As for Celtic, they appeared to have recovered from their draw at Hibernian last weekend with a 2-0 triumph over Cluj in the Europa League on Thursday.
And the result at Livingston could see Celtic vacate their place at the top of the Scottish Premiership for the international break if Rangers get a result against Hamilton Academical.
Neil Lennon made only one change from their win over Cluj with right-back Moritz Bauer replacing Hatem Elhamed.
Gary Holt’s side, who had lost their previous four matches, including three in the league, showed four alterations with goalkeeper Matija Sarkic, Jack McMillan, Keaghan Jacobs and Dykes back in the side.
The sodden artificial surface was proving to be a leveller and the home side, all hustle and bustle, came close in the 12th minute when defender Jon Guthrie side-footed a cut-back from Nicky Devlin past the post from six yards.
A flurry of activity at both ends saw Livi winger Steven Lawless test goalkeeper Fraser Forster with a low drive from outside the box before Sarkic parried an Odsonne Edouard drive wide for a corner which was headed over by Christopher Jullien.
The game’s complexion changed markedly when Christie went in high on Robinson in the middle of the pitch with Collum having no hesitancy in flashing red.
The champions’ response was to increase the tempo and moments later defender Kristoffer Ajer prodded the ball into the arms of Sarkic after breaking into the box.
Livingston’s opening goal was well-worked.
Lawless knocked the ball from wide into Robbie Crawford just outside the box and when he slipped in Robinson, he quickly drove high past Forster from 16 yards.
With that stunning strike, the prospect of a shock Livi win was on the cards
Lennon reshuffled with Ivorian striker Vakoun Issouf Bayo replacing James Forrest and the Hoops went all out for the leveller.
Sarkic made saves from Edouard and Mohamed Elyounoussi before Forster’s feet blocked an effort from Robinson in a Livi counter-attack.
Celtic’s pressure and corner count increased but one long free-kick from Sarkic went all the way through to Dykes, who ran past Jullien and calmly lobbed the ball over Forster for a victory which put an unlikely dent in the Hoops’ title hopes.