Shola Ameobi's second-half penalty had given the Magpies the lead but substitute Sanmi Odelusi looked to have salvaged a point for the U's with his 89th-minute strike.
However, there was time for more drama as Ryan Yates glanced home a header to seal victory for Notts in a last-ditch 2-1 win which sent Meadow Lane barmy.
The result keeps Kevin Nolan's level on points with League Two leaders Luton Town and five points above the playoff places, a great position to be in ahead of a busy festive period in December and early January.
How have the Notts County fans, players and manager reacted to the win? Here's a collection of the best responses.
Kevin Nolan
"It's a fantastic win. Colchester are a good outfit, they've asked us a lot of questions and taken us all the way to the wire.
"We had to be on our mettle on both sides of the ball. They caused us a few problems but I feel we contained them quite well.
"In the first half they played us really well and we didn't get any momentum or creativity going but in the second half, we dominated and looked more likely to win the game."
Ryan Yates
"I'm absolutely buzzing. We dominated the second half and got sucker-punched on the counter for their goal. But to come back and win shows the spirit of the team.
"They were a good side. They did both sides of the game really well. They were winning more second balls, putting it in behind us and making things difficult.
"We came in disappointed at half-time but had some firm words from the gaffer and put in a better performance in the second half."
The players on social media
The Black and White Army
Who r ya?? You Pies: 3 very good points against a good side who caused us problems, and what were those offials doing some strange decisions to say the least, but the lads kept going to the wire and got a deserved win, well done from me, COYP
Chris: First half was very daunting to watch, I didn't feel very comfortable and I felt it was a matter of time before they scored. However, they didn't quite have that threat on goal. I do feel they was unlucky, as Duffy elbowed and force one of the Colchester players down onto the ground (penalty any day for me). Thankfully it wasn't given, but I felt the first half was extremely poor. Second half, brilliant - things really clicked and I honestly felt we pressured them very well. We was unlucky at times as our build-up play was amazing and just the finishing which lacked, yet things can't be faulted. I felt the whole squad really put a solid performance and worked well. We deserved the points but what a fantastic save by Fitzsimons!
Elite_pie: A difficult game to sum up, I can understand why the Colchester fans would go home disappointed, but after a poor first half I think we just about did enough in the second to earn the 3 points. This is just the sort of game we would have gained a point at best over the last few seasons, but Nolan seems to have instilled the 'never say die' attitude he always showed as a player into a fairly limited squad. It counts for a lot in this division, I've lost count of the number of points we've dropped at Meadow Lane simply because the away side were organised, worked hard, and wanted it more. To be sitting where we are on 41 points after just 20 games is way beyond my expectations, long may it continue.
Liampie: i am pleased as i thought it was going to end up a draw before the game. even at times during the match i thought it was and it probably should have been with their penalty but i do also feel we was good enough to win. luton is shaping up to be the exeter kind of game now.
TheSkipper: Yesterday is the type of game last season we would have lost and I thought Notts did a great job at pulling ahead once they had scored. I did not see the penalty, so I can't call it but the referee did seem keen to award something in their favour. Thought Notts played solid in midfield but we do need to be more organised at the back as I am concerned about these daft penalties.
BromPie: I thought the referee was terrible, he killed the flow at times and tended to favour Colchester United. The result is just wanted we needed, so for that reason I am delighted. Notts never gave up and ended up getting what they deserved. What a result!
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