Wayne Brown's side claimed their second consecutive win at Harrogate Town with a superb comeback victory at the EnviroVent Stadium.
Jack Muldoon got the hosts off to a good start after just four minutes, slotting the ball calmly under Shamal George.
But two first-half strikes from Freddie Sears and Noah Chilvers turned the game on its head just before the break, a scoreline that would remain until the end of the ninety minutes.
Wayne Brown named a starting eleven with two changes from the team that beat Tranmere Rovers 1-0 at the JobServe Community Stadium last weekend.
The goalscorer from last weekend, Junior Tchamadeu, was rewarded with a space in the starting eleven, taking John Akinde's place, with Tom Eastman coming in for the injured Tom Dallison. Tyreik Wright returned from international duty to the matchday eighteen with a spot on the bench.
Tom Eastman's appearance put him eighth in the all-time appearance makers for Colchester United, with 433 to his name, taking him one above John Fowler.
The hosts made a quick start in the game, finding the back of the net after just four minutes, with Jack Muldoon slotting the ball under Shamal George to give his side the lead.
But they could have taken the lead even earlier, when after just two minutes Calum Kavanagh was caught in two minds whether to shoot or pass when clean through on Shamal George's goal. In the end he did neither, and the ball ran harmlessly out of play, but Muldoon's effort a couple of minutes later meant Weaver's side were ahead in the first half.
The U's had to soak up a fair amount of pressure from Harrogate's attacking line up, but Wayne Brown's side managed to get themselves back on level terms mid-way through the first half, with Freddie Sears netting his fiftieth goal for Colchester United.
On the counter attack, Noah Chilvers picked out the perfect ball for Sears, who saw Mark Oxely coming off his line and cleverly chipped the ball over him and into the corner of the net to level the game.
Wayne Brown's side were playing the counter-attacking game well against Harrogate Town's back three, finding joy down either side of the pitch. And that is where the second U's goal came from, with Freddie Sears turning provider this time.
Sears was picked out by a searching Cole Skuse pass holding up the play and allowing his fellow U's teammates to get into posistion before finding Noah Chilvers in the centre of the penalty area. And Chilvers gratefully accepted Sears' ball through, stroking his effort home just before the whistle blew for half time.
In the second half, Harrogate Town came out attacking, and looking to get themselves back on level terms, but struggled to make any in-roads on the U's goal with Shamal George remaining untested for the opening fifteen minutes of the half.
That was, in part, down to the good defensive work from the four players in front of him, with Cameron Coxe making na outstanding challenge on Luke Armstrong on the penalty spot. The Welsh full back had spotted the danger, closing down Harrogate's top scorer to shut the opportunity down quickly, picking up a knock in the process.
The pressure kept coming for the U's, with Shamal George eventually forced into a flying save from George Thomson's volley from the edge of the penalty area, but the visiting 'keeper was equal to it.
It was one of Harrogate's few shots on target during the closing stages, and the U's were perhaps a little unlucky not to add to their tally, with Sears and Hannant both going close to adding a third for Colchester United.
But after five nervy minutes of stoppage time, Wayne Brown's side claimed their second consecutive win, moving them eleven points clear of the bottom two with six games to play.
Next up for Colchester United is a home game against struggling Stevenage, at the JobServe Community Stadium next weekend.
Harrogate Town starting XI: Oxley, Fallowfield, Smith, Burrell, Thomson, Kavanagh (Power 68'), Sheron, Pattison, Muldoon (Ilesanmi 83'), Diamond, Armstrong.
Unused subs: Cracknell, Kerry, Austerfield, McArdle.
Colchester United starting XI: George, Chambers, Wiredu, Hannant, Skuse (Welch-Hayes 84'), Sears, Chilvers, Kenlock, Eastman, Tchamadeu (Judge 68'), Coxe.
Unused subs: Hornby, Andrews, Akinde, Huws, Wright.