The U’s named an unchanged starting eleven for the fifth league game in a row, as Joe Dunne kept faith with the side that had picked up three wins in those first four fixtures.
Two behind at the interval, the visitors had a number of chances in the second but a combination of wasteful finishing and some great defending by the U's ensured that they marched on up the League One table.
Having ridden the first fifteen minutes, the U's stormed into the match with a superb display of football that saw them notch two and threaten to get a hatful more as Carlisle clung onto the game by their fingertips.
A stunning first half display was enough to guide the U's to a third successive victory and a fourth win in five.
The visitors started in lively fashion, but the U’s kept them at bay in those first ten minutes, Garner coming closest as he stepped back inside to bend one past the far post.
The U’s grew into the half and their best chance came from a flowing move, with Wordsworth’s effort on the angle being well saved by Gillespie.
Eastmond then burst into the box and forced a good stop out of the young Carlisle keeper, who then blocked Ibehre’s follow up in the same move.
It was better from the U’s, and they got the goal their efforts deserved midway through the half.
It was a sensational winding run from Watt that beat two defenders, and he rounded Gillespie to get to the byline and kept his head to slot across for Eastmond to react and tap home from close range.
Higginbotham burst into the box and went to ground under pressure, but the referee had no interest in giving the spot kick.
The U’s doubled their advantage on 30 minutes and it was that man Watt in the thick of it again. He got the ball on the left hand side, controlled it and darted a brilliant low cross into the danger area.
Ibehre was the man who was quickest to react again, stabbing in a great effort into the roof of the net past the helpless Gillespie.
At two up, the U’s were seeking blood and came close to a third on three successive occasions as they penned in the visitors.
First Wordsworth’s low volley on the edge of the box was backheeled towards goal by Watt, forcing a good stop out of the keeper.
Next, Bean’s bursting run saw the keeper turn it behind from a corner, from which Eastman forced another fine save out of the beleaguered Gillespie.
At two up though, the visitors were still in the game and a header from a corner clipped the top of the bar before Garner’s hesitation in a great position allowed Wilson to get back in and block the ball.
The U’s could have further extended their lead, though, as they hit the post just before the break, whilst Watt then had a shot from just outside the area, which went wide to the right of the goal.
Confident after a great first half, the U’s had to make a change at the interval as John White made his second league appearance of the season, replacing the injured Brian Wilson.
As in the first half, the visitors started brightly and Edwards spurned a good chance from a header, before Higginbotham slid in Simek, who dragged his shot wide of the far upright.
Garner then spurned a golden opportunity again, ghosting away from his marker from a free kick but heading wide from eight yards out.
The visitors were well on top at this point and two good saves from Cousins ensured that their advantage was protected as they looked to get a foothold in the game.
Next, Garner wriggled free into the box and as it looked like he might go for goal, he went to ground under pressure for the second time – and again the ref waved appeals away.
The U’s lost the impressive Watt to injury on the hour mark, but had more than able cover at the back as Sears came on.
But whilst the visitors prompted and probed, the U’s efforts off the ball ensured that through balls were often over egged and out for goal kicks.
Having been under that pressure, it was the U’s who were next go to close, though.
Sears picked up a miscued Carlisle header and helped it into the path of Ibehre, who spun on a sixpence to fizz one just wide of the post.
Sears then had another effort deflected behind from a corner, from which Eastman got up highest but wasn’t in control of the ball as he headed wide.
The ex-West Ham man got away again as he slid one in for Ibehre, who was denied at the near post.
At the other end, Chantler found himself in plenty of space before curling a shot that curled towards rather than away from Cousins.
Then Rose produced a sensational tackle to deny Garner, as he went to shoot inside the U’s area.
The U’s kept trying their passing game, and a sharp interchange of play from Wordsworth and Massey saw the latter dart into the box and smash in a low shot that Gillespie did superbly to turn around the post.
The chances kept coming and visiting substitute Potts looked like he might have a sight of goal when it eluded Cousins, but it flashed into the side netting.
The visitors had had some great opportunities and another great one went begging with six minutes to go, as a header found Berrett in acres of space, but he somehow headed wide.
But the U's two goals were enough to keep the momentum going into a double away day this week.
At the other end, substitute Henderson was agonisingly close to adding a third, Sears’ great work down the right just missing his team-mate’s outstretched boot.