Victor Wanyama and Tony Watt fired the two goals that defeated mighty Barcelona, the Spanish giants considered the best club side in world football.
Despite a late goal by Lionel Messi, the Hoops hung on for a famous Champions League victory.
It is the first time Barcelona have been beaten in any competition this season.
More than 55,000 fans packed into Celtic Park for the match – which saw Celtic exact revenge for their last-minute 2-1 defeat in Barcelona two weeks ago.
And the win has not only boosted the chances of Celtic qualifying for the knockout stages, it has increased the value of the squad by millions.
Kenyan midfielder Wanyama – valued by manager Neil Lennon at £25million before the match – again gave a world-class performance.
Others like keeper Fraser Forster and teenage striker Watt saw their stock rise dramatically.
Among those at Celtic Park was long-time Celtic fan Rod Stewart, who was in tears as he watched his heroes defeat the mighty Catalans.
The celebrations included renditions of You'll Never Walk Alone and I Just Can't Get Enough.
Reaction to the result among football luminaries was swift and incredulous.
Former Bolton manager Owen Coyle said: "It's an unbelievable night for Scottish football.
"Celtic have just taken care of the best team in the world. That's why we love this game."
Ex-Scotland manager Craig Brown said: "This is one of the famous victories in the history of Celtic.
"I thought it would be a close game. But I didn't think for one minute Celtic would score – never mind win."
Celtic boss Lennon described the win as one of the proudest moments of his footballing life.
He said: "It's right up there, one of the proudest moments of my career.
"This is monumental. On the anniversary of club it was a very special occasion."
HE continued: "We wanted to do ourselves justice and we surpassed that. We've beaten the best club in the world.
"It was a stiff examination and we came through it with flying colours."
Goalscorer Watt, who hails from Coatbridge and is still only 18, said: "It will take a couple of hours for that to sink in.
"I just saw Victor Valdes and put it in the corner. I couldn't believe it, it's probably the best moment of my life.
"We'll look back at it when I'm older and say, 'wow, we've beaten Barcelona in the Champions League' – it doesn't get better than that.
"The crowd were like a 12th man, I've never heard anything like it, the place was rocking."
Celtic goalkeeper Forster said: "It's tremendous. Words can't describe it.
"We put in so much effort away and couldn't see it through, but today we have and we're delighted.
"We have a fantastic squad; whoever comes in can do the job.
"Even with injuries everyone was tremendous and played their part.
"We deserved it in the end. We defended really well.
"We had a good look at them a couple of weeks ago and knew what we wanted to do.
"We didn't do much wrong in the Nou Camp, but we did it all today."
Celtic goalscorer Wanyama said: "This is unbelievable... we're very happy. I can't describe it – we're very, very glad. It's unreal.
"We beat one of the best teams in the world. It was not easy and we're just happy."