Some curious defending by Celtic defender Shane Duffy allowed Ilkay Durmus to fire in what turned out to be the winner in the 37th minute to give the Paisley side their first victory in the east end of Glasgow since April 1990.

Lennon described the afternoon as the lowest point of his two spells as Celtic boss and the Hoops’ quest for 10 successive Scottish Premiership titles looks over as Old Firm rivals Rangers remain 23 points clear having played two games more.

Scotland midfielder McGregor, captain again in the absence of Scott Brown, told CelticTV: “It was really poor again. We are not learning lessons that we have to.

“Granted it is a new, younger feel about the squad but there is no doubt we are in transition in terms of being able to consistently perform.

“We have bits in games where we look alright and then we go to sleep, we don’t do the basics.

“You see the goal, it is just organisation and the second one is the same, we miss the first tackle and then we are all over the place.

“We have so much learning to do and the only way to do that is to keep working and  try to stay positive  in terms of learning but at the same time we have to get results and we are not doing it so it is not good enough.”

McGregor said the midweek performance was “excellent” but because of a number of young players in the side “consistency is going to dip”.

He said: “You see our team now, it is fairly young and we have to learn and that is going Wednesday – Saturday – Wednesday- Saturday all the time.

“The boys will get there but that is where we are at, at the minute.”

While much of the focus was again on Lennon’s future and Celtic’s continuing struggles, St Mirren manager Jim Goodwin hoped his side would get the credit for their victory.

“I don’t think Celtic played particularly poorly,” he told SMTV. “I think it was down to the effort and organisation of the boys in black and white. They didn’t leave Celtic any gaps or spaces.

“Jak Alnwick has had probably the quietest afternoon a St Mirren goalkeeper has had here for years.

“In fact we had more shots on target than Celtic. I don’t know when the last time that happened.

“I told the players we can’t get too carried away. I want them to enjoy it but in a professional manner because we’ve got another huge game coming up on Tuesday.

“And again I will have to rotate the squad because we had one or two lads coming off with cramp or knocks. We had four or five in with the physio.

“We will assess the squad on Monday, see where we are at and try and put out a side that is good enough to beat Hibs.”