Lewis Thomas’ penalty save and substitute Jack Aitchison’s goal earned Forest Green a 1-0 win at Cambridge.
Aitchison struck to snatch the points 12 minutes from the end, running in from the left and smashing in off the upright past Dimi Mitov.
Rovers were indebted to Thomas, who stooped to his left to keep out Marc Richards after referee Anthony Backhouse’s assistant flagged for a spot-kick following a shirt pull on George Taft after 66 minutes.
That came moments after Rovers captain Joseph Mills had superbly headed Paul Lewis’ header away from underneath the crossbar.
The bar had earlier come to Forest Green’s rescue to deny Luke Hannant’s fine effort from just outside the box shortly after the interval.
In the first half, Thomas made an important save down low to deny Liam O’Neil as Lewis was again the provider with a low centre.
Forest Green, who had manager Mark Cooper booked 20 minutes from time, offered little but could have capped their win late on, only for Aitchison to hit a post.
Report supplied by PA Media