Carlisle United set a new club record of eleven games unbeaten as their amazing start to the season continues.
Colchester enjoyed a calm period of early possession but they were made to defend when Shaun Miller spun off his marker's shoulder on the edge of the area. His cross earned a corner and he was involved in an intricate set piece routine which opened a gap for Grainger to shoot. It came off a defender and was an inch away as it flew past the target.
Grainger went for a wicked inswinger this time and a flick from Kennedy invited Raynes to attack the ball. He got his forehead to it but it wasn't enough to send it into the net.
Set pieces caused problems as the home side found good pace and power but another wicked Grainger curler beat everyone as Raynes once again put everything into trying to get a touch.
The U's chose their moments to attack but United held their concentration to keep them at arm's length through what was a cagey period of the game. A weak effort from distance from Wright did little to concern Gillespie as he watched it bobble behind.
Shaun Miller created a chance for himself when he went on a 20-yard run which saw him bend along the line of the 18-yard box. His shot was on target, until it struck Kinsella's hand, but referee Graham Salisbury showed no interest at all in answering the appeals.
Raynes had to block from Fosu, as Colchester edged their way into the game, but there was little room for movement for either side in the middle areas as every loose ball was closed down.
The U's put balls into the box as they enjoyed a good spell and Grainger had to head over his own bar when Fosu bent a wide free kick at the near post. Carlisle cleared the corner and a long ball forward was expertly controlled by Shaun Miller. He popped the cross high and a volley from Adams was blocked after Kennedy had attempted an acrobatic overhead kick.
Johnstone headed a deep corner well wide as Colchester kept pushing for a way through, but it was Carlisle who felt aggrieved again when Kennedy latched onto a cross from Joyce with a firmly struck volley. The ball once more hit a hand and Kennedy was incensed as the referee waved his protestations away.
Carlisle finished the half on top and great movement from Shaun Miller brought Adams into play as the striker clipped a high ball into his path. A perfect volley looked to be top corner bound until Prosser got his body in the way.
United came out of the blocks on fire at the start of the second half and Walker had to readjust to palm a deflected Grainger free kick away from his bottom corner. The ball was forced behind, under pressure from Wyke and Raynes, and the latter was unlucky to see his header from the corner tipped onto the bar by the keeper as he saw it late.
Another great Grainger delivery found Raynes at the back stick and Colchester failed to react as the ball got stuck on the six-yard line. Wyke had a dig, as did Tom Miller, but Jason Kennedy arrived in the nick of time to smash it into the roof of the net.
Carlisle took a real risk on the hour when they tried to play their way out from deep. An underhit pass from Gillespie had Johnstone interested but the keeper redeemed himself to close down the space and smother the danger.
Colchester should have equalised moments later when Szmodics beat the offside trap to ghost into the box. He trapped the ball beautifully but was left to regret his decision to go for the lob when all it needed was a calm head and a sure touch.
The home response was to burst forward in numbers and Wyke did well to send Shaun Miller away on the right. He exchanged passes with Joyce and his cross appeared to be set for Kennedy as he bent his run to find space. The midfielder took his eye off the ball at the optimum moment and he failed to get a touch.
Away pressure built up but Gillespie remained largely untroubled as his defence soaked up the corners and crosses into the box. But the home goal lived a charmed life when a flick on sat up for Prosser. His downward header was going in until substitute Jabo Ibehre stuck a leg out to stop it on the line.
The Carlisle favourite had an even bigger say at the other end as he won a corner for his side to ease the growing away momentum. And he inevitably bagged against his former club when he nodded the delivery down and into the ground. Walker got his hands all wrong and his touch served only to push it over the line.
Ibehre sent another header at the keeper and blazed a blistering shot over the bar as United started to dominate, and Slater wasn't too far away at the other end when he bent wide from 25-yards.
Referee Graham Salisbury was replaced by his fourth official Simon Clayton in time added on, but it was already job done for Curle's record breakers as they celebrated a very hard-fought win.
Carlisle United - Kennedy (51), Ibehre (79)
Colchester United - Prosser (49)
Carlisle United - Gillespie, T Miller, Raynes, Gillesphey, Grainger, Kennedy, Jones (Devitt 87), Joyce, Adams (Lambe 65), Wyke, S Miller (Ibehre 73). Subs - Crocombe, Ellis, Brisley, McKee.
Colchester United - Walker, Brindley, Prosser, Wright (Porter 78), Szmodics (Kamara 85), Johnstone, Eastman, Slater, Guthrie, Fosu (Sembie-Ferris 62), Kinsella. Subs - Bransgrove, Vincent-Young, Wynter, James.
Referee - Mr Graham Salisbury
Attendance - 4,516 (156 away fans)