Playing a more expansive game than in recent weeks Blaydon were in control for most of the 80 minutes but had to pull out the stops in the closing stages and even then the home side had the last word.
It was nip and tuck at first but Blaydon gradually assumed control and opened the scoring when full-back Nathan Bailey put a penalty to the corner and No8 Jason Smithson was driven over from the maul.
Andrew Baggett added the conversion,as he did to the other two Blaydon tries, but Cambridge were soon on level terms when the visitors knocked on and scrum half Ross Kevan broke from 30 metres to leave the defence for dead, Elliot Vale converting.
By half-time Vale and Baggett had each added a penalty to make it 10-10 but a galvanised Blaydon made all the running after the break and following some effective forward play Bailey scooted in near the posts. Baggett again added the extras and then a penalty to make it a comfortable lead but back came the home side to pull it back with 6 points from Vale and Will Hooley.
Now realising that they would have to work hard to defeat the relegation doomed Cambridge the Crow Trees side reverted to Plan A and turned down a kickable penalty in favour of a line-out drive. The move was completed with consummate ease, the pack marching on from 20 metres for lock-forward Chris Wearmouth to touch down and Baggett to take his total to 12 points.
With just five minutes remaining the game looked in the bag but there was still time for a never say die Cambridge to grab a second try through Steven Hipwell, and Hooley slotted over the conversion with the final kick of the game.