Doncaster Rovers took the points on Saturday as two penalty kicks proved to be the difference at the Keepmoat Stadium.
The U's missed a golden chance to take the lead early on as Chris Porter missed his spot kick and, after an evenly contested first half ended with the home side one up, Rovers sealed the win when Nathan Tyson slotted home from twelve yards.
The home side had had the better of the second half, but even then the U's will look to chances early in the second period when both Bonne and Porter had sights of goal.
The defeat, along with results elsewhere, put the U's back into the bottom four and set up a big home game on Tuesday against Notts County, who sit four points above Tony Humes' men.
There were two changes to the U’s starting eleven, with Karleigh Osborne and David Fox coming in for Matthew Briggs (illness) and Tom Lapslie (injury). Alex Wynter moved across to left back as Osborne made his debut.
Both teams had early chances, with Hewitt crossing dangerously to win a corner and Main doing similarly for the home side shortly afterwards.
From that set piece, the home side went within inches of taking the lead. Walker was unable to connect with the cross and Butler’s header came back off the inside of the post and back into the keeper’s arms.
The home side had started well, and won another corner on ten minutes that saw a header sent comfortably wide of the far post.
However, the U’s were given a golden chance to take the lead after twelve minutes. Porter was shoved in the back as Clohessy crossed, and the front man picked himself up to take the spot kick but put it high and wide.
Rovers went close again on nineteen minutes. A dangerous cross from the right hand side saw Razak rushing in and his glancing header skimmed the top of the crossbar and away to safety.
The U’s were dangerous in their own right, though, and Hewitt got away on 27 minutes after a fine through ball. He saw off his man, cut inside and curled inches wide.
At the other end, Warbara opted for a similar low shot, this time to the near post with players waiting, but Walker collected well.
Hewitt was proving to be the U’s main threat, and robbed his man just inside the Rovers half on 33 minutes but his shot from distance was straight at Bywater.
Rovers got their noses in front on 40 minutes, though. A ball forward eluded Clohessy and although the first shot was blocked, Stevens drove through a mass of bodies to make it 1-0.
That’s how it stood at the break, and the U’s started the second half seeking an equaliser.
Gilbey went into the referee’s book early in the second period, before the U’s almost got themselves level.
Massey drove into the box past two men and his cross/shot was deflected up into the air. It eluded Porter and Bonne couldn’t quite connect to turn it home.
Goalscorer Stevens was in the right place at the right time on 50 minutes. Massey sent over a cross that Porter flicked on and Bonne looked set to nod home before the left back tucked in and headed away.
The duo combined well again on 54 minutes as a ball in from the right this time was headed towards goal by Bonne, and this time Porter tried to nod home, but helped his effort over.
The home side should have doubled their lead on 68 minutes as they escaped on the counter with men to spare, but Main shot straight at Walker.
However, the keeper was beaten with eight minutes to go when the home side converted a penalty.
It seemed harsh on Wynter, who went to hook the ball clear with his man behind him, and caught the Rovers man. The referee pointed to the spot though, and Tyson made no mistake.
And, whilst there were six additional minutes, where Healey tested the keeper more than once, the home side took the points and the U's will have to go again on Tuesday.