A tight first half saw only long range efforts from the U's testing home keeper Ben Garrett, while Elliott Parish had only one effort to deal with, tipping over a George Ray header.
George Moncur opened the scoring from the spot but the U's were denied at the death when Saunders equalised.
U’s boss Kevin Keen made two changes to the starting line-up, bringing in Alex Gilbey and Macauley Bonne.
Tom Lapslie and Elliot Lee were the players to drop out, as the U’s took on bottom placed Alex.
And it was the U’s who dominated the first half, having the lion’s share of possession without being able to get onto the scoresheet.
All the efforts towards the Crewe goal was relatively easy for Garrett, with Alex Gilbey getting away an array of shots.
Owen Garvan and Frankie Kent had efforts first though, the first straight at Garrett and Kent’s flying high and wide.
Gilbey’s first shot was an off target volley on twenty minutes two more that , followed by one well over and one saved comfortably.
At the other end, a good challenge from Tom Eastman denied Haber in the first home attack of any intent.
The U’s had a decent chance to open the scoring on thirty three minutes, but Joe Edwards’ first touch let him down after he was found with a great ball from Garvan.
George Moncur was the next U’s player to try his luck from outside the box, following flicks from Chris Porter and Macauley Bonne, but again Garrett was easily up to the task.
On forty minutes, a wayward pass across defence from Kent only found Haber but Eastman was alert enough to deflect the shot from the corner.
Parish was called into action from the set piece, tipping Ray’s header over the bar for another corner, which came to nothing.
That was the final action of the first half, a half in which the U’s dominated possession but failed to deliver in the penalty area.
The second half began in the same vein, with neither keeper tested until just before the hour mark.
Gilbey was again the one trying his luck, hitting a rebound shot after Moncur’s effort was blocked.
On sixty four minutes, Gavin Massey went round the full back but had to be content with a corner for his efforts.
It was enough for the U’s to take the lead, with Frankie Kent fouled as he got on the end of the set piece, with Moncur calmly sending the keeper the wrong way from the penalty spot.
The goal spurred the home side into action and Jones was denied by Parish after Massey lost possession.
Then Kent had to make a last ditch block before Parish had to be quick to get to the ball first from Eastman’s underhit back pass.
Parish also had to save from a David Fox free kick, as the U’s came under late pressure.
That pressure paid dividends in injury time though, as Saunders headed home a near post corner to make it 1-1.
The draw closed the gap to eight points, with nine to play for in the three remaining games.