The U's have been beaten 2-1 at Bristol City despite a display where they matched up the promotion hopefuls.
George Moncur opened the scoring on nine minutes, his second of the season, sweeping home his shot after good work from Sean Clohessy.
But it only took the hosts fifty one seconds of the second half to equalise through Wilbraham, and the striker scored again on sixty eight minutes to make it 2-1.
U’s boss Joe Dunne was forced into a change at centre half, with skipper Magnus Okuonghae unavailable due to his red card at Charlton.
An appeal was unsuccessful and Dunne bought in Frankie Kent into the heart of defence alongside Tom Eastman.
There were two other changes in the U’s starting line, with Sam Walker and Marcus Bean replacing Chris Lewington and Dominic Vose respectively.
The bench had a youthful look to it, with Bonne, Szmodics, Curtis and O’Donoghue all still in their teens.
The hosts reverted to last weekend’s starting eleven, after making eight changes for the Capital One Cup defeat to Oxford United in midweek.
The home side started the game with plenty of possession in the middle third of the pitch, but the U’s were keeping their shape very well and protected their area.
It was the U’s who had the first chance of the game, and made it pay as they went ahead through George Moncur.
Tom Eastman hit one of his trademark diagonal passes, which Freddie Sears kept in play in the corner and rolled it back for Sean Clohessy to cross.
The cross was cleared back out but Cunningham’s touch let him down and he was dispossessed by Clohessy.
Showing great composure, Clohessy picked out Moncur, who calmly swept his right foot shot low into the bottom corner for his second of the season.
The goal certainly quietened the home crowd and it took Bristol a good few minutes to get their game going again.
Sam Walker made a comfortable save on sixteen minutes, as he dived to his left to take a Wilbraham header.
The U’s keeper was then quick off his line to get there before Baldock before the home side missed the target on two occasions.
First, Freeman struck his free kick over the bar and then Wilbraham followed suit with a looping header.
Ten minutes before the break, the U’s nearly doubled their lead, with Jabo Ibehre the unlucky player.
A long ball gave Ibehre a run but he would have been surprised to see Fielding coming well out of his goal down the U’s right.
The U’s striker saw his opportunity and lofted a shot over the keeper from an acute angle – unfortunately, it just cleared the bar as well and landed on the roof of the net.
In the first half, he U’s had shown great discipline and commitment to the system Dunne had asked them to play and punished the hosts with Moncur’s goal.
Whatever Steve Cotterill said to his side worked, with Wilbraham equalising within a minute of the start of the second half.
The U’s reacted well though, with Ibehre and Gilbey testing Fielding in the home goal.
Surprisingly, it was the U’s who were having the better of possession but they did have to get back quickly on two occasions as the home side broke.
Gordon blocked a goalbound shot from Smith in the sixty eighth minute but the resultant corner led to City taking the lead.
Sam Walker came to the near post to collect but was beaten to it by Wilbraham, who flicked his header into the empty net.
Dunne made all three of his changes as he looked for a way back, with Szmodics, Vose and Holman replacing Moncur, Massey and Ibehre.
Vose shot wide just after coming on and then Clohessy’s cross had to be tipped over by Fielding.
The same two U's players then combined, with Clohessy shooting over when well placed in the box.
Bristol City saw out the remaining few minutes comfortably, and the U's had to leave Aston Gate empty-handed.