The U's made it seven games unbeaten since Aidy Boothroyd's appointment, and gained another three points thanks to a second half winner from Kayode Odejayi.
The loanee could have scored in the first half but powered home a header from a corner to give the U's victory.
U's boss Aidy Boothroyd named an unchanged starting eleven, having seen them win consecutive home matches against Charlton and Huddersfield.
Former U's boss, Geraint Williams, made four changes from the side that beat Brighton in the Johnstone's Paint Trophy, including the recall of Scott McGleish.
The game got off to an explosive start, with the U's almost having the ball in the net and the O's keeper stretchered off in the very first minute.
A long ball was headed down by Wordsworth and an interchange of passes between O'Toole and Platt ended with O'Toole challenging keeper Jones.
The ball bounced goalwards and was cleared off the line, with Jones looking unconscious a few yards out. There was a real concern for his safety and it was a good few minutes before he was carried off with an oxygen mask and neck brace in place.
This incident seemed to affect the O's and he U's put pressure on, with Platt heading wide Odejayi having a shot blocked.
The U's loanee Odejayi then had two more chances, the first another shot being blocked and then heading wide of substitute keeper Glenn Morris.
It took the O's a while to get any foothold in the game but it was they who had the next chance, with Scowcroft almost getting on the end of a rebound after Ben Williams had saved from Townsend.
With forty minutes gone, Odejayi had the best chance of the match when he created a yard of space from a Wordsworth corner. Unfortunately, his header flew wide and the chance was gone.
A couple of minutes later, former U's striker McGleish shot wide before Odejayi headed straight into the keeper's arms from another corner.
The final action of the half came well into the five minutes of injury time, as Scowcroft hit a twenty yard shot over after good work from McGleish and Townsend.
U's boss Aidy Boothroyd would have been pleased with his side's general play but frustrated that the pressure wasn't converted into goals.
The second half started with the U's continuing the pressure, and only a fantastic save from Morris prevented O'Toole opening the scoring.
Lisbie had made great strides down the right and an intelligent pull back found O'Toole. O'Toole did nothing wrong as he steered his shot goalwards but saw the effort tipped wide.
On fifty three minutes, the U's did open the scoring, as Odejayi headed powerfully into the roof of the net. Wordsworth whipped in a corner and from O'Toole's flick on, Odejayi made no mistake.
The O's tried to get back into the game but the U's were still having the better of the play and had to deal with injuries as well.
John White was stretchered off with a knee injury and Odejayi also took a knock and it was substitute Steven Gillespie who had the next effort on goal.
He got in behind the O's defence and under pressure, could only shoot wide from an angle.
The O's did test Williams in the final stages but the U's stopper was up to the task and tipped along range effort over the crossbar.
The referee allowed six minutes of injury time but the U's comfortably saw it out to get another valuable three points.