Celtic needed an 88th minute winner from Nicolas Kuhn to beat Ross County 2-1 and maintain their 100% record in the Scottish Premiership this season.
The Hoops were hoping to forget their chastening 7-1 Champions League defeat at Borussia Dortmund in midweek.
But Brendan Rodgers' men had to come from behind in the Highlands after conceding for the first time in seven league games.
Ronan Hale needed two goes to score from the penalty spot to put County in front after a Liam Scales handball.
The striker's first spot-kick was saved by Kasper Schmeichel, but the Danish international had strayed off his line in making the stop.
Hale made the most of the reprieve to fire the home side in front just before halftime.
Rodgers had made just three changes from the side that was taught a lesson by last season's Champions League finalists.
And it was not until he injected fresh legs from the bench that Celtic came to life in the final half hour.
Alistair Johnston deflected in Callum McGregor's shot to level 15 minutes from time.
The same two players then combined to free Kuhn down the right and the German winger cut inside to score his sixth goal of the season.
Victory takes Celtic three points clear of Aberdeen, who host Hearts later on Sunday.
Rangers now trail their Glasgow rivals by eight points ahead of St. Johnstone's visit to Ibrox.