A first half strike from Jack Payne was enough for the visitors to take all three points in a tightly contested affair at the JobServe Community Stadium.
Payne rolled the ball beyond Shamal George mid way through the first half, to give his side a lead that they would hold on to until the final whistle as John Yems' Crawley Town picked up their first points on their travels this season.
The U's weren't without their chances and came out of the blocks quickly in the first half, but were unable to break through. It was a similar story in the second half, with Crawley Town goalkeeper, Glenn Morris able to collect anything his defence didn't.
The U's lined up with two changes from the last game, with Luke Chambers missing through suspension.
Tom Eastman came in to take his place in the starting eleven, whilst Luke Hannant was swapped out of the line up for Sylvester Jasper.
The game had a lively start as the U's were quck to get the ball forwards and attack the visitors' goal. Early off target attempts from Wiredu and Sears sandwiched a shot from Judge that Morris had to be alert to cover and palm away in the opening ten minutes of the game.
But the U's were left ruing their missed chances when it was the visitors who took the lead with just under twenty-five minutes of the game gone. Will Ferry was the provider and showed what he could do moments earlier when he cut in and fired an effort straight at Shamal George.
This time though, he looked up and unselfishly passed the ball on to Jack Payne, who rolled the ball calmly into the bottom corner to give Crawley Town the lead in the game.
The visitors then had their tails up looking for a second, but although they were able to get forward, their efforts on goal were limited. The remaining best chance of the first forty-five minutes fell to Nick Tsaroulla who shot over George's bar from outside the area.
Colchester United were pressing to get themselves back in the game after a strong start but unable to make any headway before half time. Freddie Sears saw a goal-bound effort blocked away by Dallison after Wiredu had spotted his teammate free on the edge of the area, with Sears' low strike blocked and cleared.
Sears had another effort five minutes before the break when Jasper's nifty flick had allowed him space on the right hand side of the penalty area, but he was forced wide, with his shot blocked away.
The visitors came out in the second half, as every defending team would, taking their time over each goal kick and throw in, but the U's were wise to it and happy to give the ball back quickly to speed them on.
With superior possession, the U's were looking to break down their opponents and had a flurry of chances in a short spell fifteen minutes after the break.
Frank Nouble was at the centre of them, seeing two efforts saved well by Glenn Morris in the away goal. The first was after a quick turn, receiving the ball from Sears, Nouble span and shot a low effort with the Red Devils' 'keeper able to get down to it.
The second, Frank tried to use power to beat the shot-stopper. From a tight angle, Nouble smashed the ball towards the far post with the outstretched hand of Morris palming the ball away.
Nouble tried to turn provider for Sears, laying the ball to him in an almost identical place frmo his first effort, but quick defending from Tsaroulla prevented the ball from reaching the target as the U's pressed for the equaliser.
Brendan Wiredu was withdrawn from action with twenty-five minutes to go in an attacking change for the home side. Armando Dobra came on in his place, with his first action playing the ball along the ground to Sylvester Jasper, whose rising effort was caught and held by Morris.
The U's found it difficult to create many more clear cut chances with a resilient Crawley defence holding srtong towards the end of the game.
There were half chances Dobra and Smith, but they didn't trouble Glenn Morris as time was running out for an equaliser.
In the end, Crawley Town held out for their first points on the road this season as the U's are still hunting for their first home win.
The defeat means that Colchester United fall to sixteenth in the table, while Crawley leapfrog the U's up to fourteenth.
Next up for Hayden Mullins' side is a trip to tenth place Swindon Town next Saturday afternoon, with the Robins drawing 1-1 with Northampton Town in their most recent fixture.
Colchester United starting XI: George, Smith, Wiredu (Dobra 66'), Skuse, Nouble, Judge, Sears, Jasper, Eastman, Daniels, Coxe.
Unused subs: Turner, Clampin, Hannant, Chilvers, Tchamadeu, Tovide.
Cralwey Town starting XI: Morris, Francomb, Dallison, Powell, Nichols (Appiah 84'), Ferry, Ashford (Nadesan 46'), Tsaroulla, Payne, Lynch, Hessenthaler.
Unused subs: Jones, Davies, Gallagher, Bansal-McNulty.