...but have concerns over Eastmond injury.
U's first half: Cousins, O'Donoghue, Kent, Eastman, Wilson, Bean, Eastmond (Sanderson), Izzet, Massey, Sears, IbehreU's second half: Phillips, Olufemi, Gilbey, Okuonghae, Duguid, Bond, David Wright, O'Toole, Drey Wright, Morrison, Cook
As time ran out, Jack Cawley charged down a Phillips clearance, which went just wide, ensuring the U's began with a win.
David Wright stood up a cross to the far post, where Drey Wright controlled it before stretching to stab it in the far side of the goal.
Bond took on a shot from distance, which the keeper turned away, before the U's took the lead with seventeen minutes to go.
Shortly afterwards, a Callandar shot slipped out of the grasp of Shaun Phillips, who grabbed at the second time of asking.
Clinton Morrison, twice, and Drey Wright had both been denied by brave blocks, before a well worked move saw a low Drey Wright cross turned home neatly with a crisp finish by John-Joe O'Toole.
However, they stepped up the tempo at the start of the second half and got their rewards.
Despite the multitude of chances the U's had created in the first half, they went in behind at the break as much of the half time conversation was about the injury to Eastmond.
The Heybridge keeper pulled off another good save from a driven Sears effort before ex-U's youth teamer Russell Malton volleyed over from a well worked set piece.
However, they found themselves behind at the mid-point of the half, as Callandar slid in Newson, who kept his cool to draw Mark Cousins and slide the ball in the back of the net.
The U's had dominated possession in the first quarter of the game, with Freddie Sears and Gavin Massey both going close as the game took shape with the U's controlling the game.
The ex-Arsenal midfielder was caught with a crunching tackle that left him writhing in agony on the pitch before being taken off in an incident that angered the watching U's bench.
They fell behind in the game before fighting back for victory, but the greater concern will be an injury to Craig Eastmond that saw him taken off on a stretcher in the first half. The U's got their pre-season schedule off to a winning start on Wednesday, with an assured performance against Heybridge Swifts.