Celtic manager Brendan Rodgers paid tribute to his players after their long unbeaten run finally came to an end.
A 4-0 defeat away at Hearts was the first suffered by the Premiership league leaders in domestic football since May 2016, a run of 69 games.
It was a run that won them the domestic treble last season of the league, Scottish Cup and Scottish League Cup, but it finally ended in emphatic style at Tynecastle.
They have been absolutely amazing over those 18 months.Brendan Rodgers
Goals from Harry Cochrane, Kyle Lafferty and two from David Milinkovic gave the home side the points in a fully deserved win.
Cochrane, aged just 16, got Hearts on their way with the first goal of the afternoon on 26 minutes, firing low into the corner with a good strike.
It was reward for a positive start from the home side and the Tynecastle faithful were treated to a second when Milinkovic found Lafferty and the striker fired home from 20 yards for his 11th goal of the season.
It was 2-0 at half-time and though Celtic had recovered from two goals down during their long unbeaten spell, they hadn't from three goals behind and that was the margin just minutes into the second half when Milinkovic got his first, rounding Craig Gordon and sending the ball home.
Any doubts about the result were put to bed when Hearts got their fourth with quarter of an hour remaining, Gordon fouling Ross Callachan in the box and Milinkovic stepping forward to convert the penalty.
The defeat means that Celtic stay two points clear of Aberdeen at the top of the Scottish Premiership with Hearts staying fifth though closing the gap on their Edinburgh rivals Hibs.
Afterwards Rodgers said that Hearts had fully deserved the win though he paid tribute to his own players.
He told the BBC: We didn't cope with their physicality, we made too many mistakes. We could have played five games today and not scored a goal.
"But I also want to congratulate my players. To have gone through 69 games and this to be their first defeat; of course it's a sore one when you are beaten like that but they can hold their heads up.
"They have been absolutely amazing over those 18 months."
Celtic play Partick in midweek before taking on Aberdeen next weekend. They are 3/10 for the win with the Dons 9/1 and the draw is priced at 4/1.
Celtic are 1/10 to win the Scottish Cup this season.
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