Celtic left Rennes with a valuable Europa League point but Vakoun Bayo 's bizarre red card left a bitter taste.
The striker, an 84th minute substitute, was sent off in stoppage time after the referee deemed him guilty of two bookable offences.
There was little to debate with his first booking, catching Rennes captain Damien Da Silva and forcing the defender to be stretchered off with a head knock.
But as Celtic went in search of a winner after Ryan Christie cancelled out M'Baye Niang's opener, Bayo found himself being ordered off.
Olivier Ntcham unleashed a fierce shot from distance which home keeper Edouard Mendy found too hot to handle.
The keeper spilled the ball and that invited Bayo to try and sniff out a rebound.
The Ivorian looks to nick it away from Mendy but the keeper just gets there first.
However, as footage below shows, there was little to no contact to warrant what happened next.
Referee Jose Maria Sanchez initially waved play on before inexplicably reversing his initial decision.
Mendy rolled over clutching his face after Bayo went for the ball and that drew Sanchez in for a closer look.
And, upon reflection, he brandished a red at the Celtic star.
It left Neil Lennon frustrated on an otherwise positive night for his side.
He said: "I’m not happy about the sending off.
"It looked to me like the referee was waving play on. I don’t know if he looked back at the goalkeeper as he was holding his head.
“There was no contact with his face at all. If anything, it was minimal across his midriff. The referee changed his mind and Bayo can feel very hard done by by that decision.
“We pride ourselves on our team discipline. Yes, we lost a player to a red card, but we feel harshly done by.
"The players acquitted themselves brilliantly in testing circumstances with the volume of crowd going up and their bench getting a little bit vociferous. We kept our composure very well.”
