Redruth came up narrowly short as they lost on the road for the 12th time this season at Cambridge on Saturday.
In a tight opening period it was the Reds who struck first through a converted Lewis Vinnicombe try.
Cambridge fought back after the break and tries from Tom Wheatcroft and Adam Barnard put them in front.
Redruth threw everything at their hosts in the closing stages, but the Cambridge defence held firm to ensure the points stayed in East Anglia.
Adryan Winnan added a second-half penalty for the Reds, whilst Wheatcroft kicked a penalty and conversion for Cambridge.
The Reds conclude their National One season away at league leaders Esher on Saturday, 1 May.