Kyle McFadzean struck three minutes into added time to earn Chesterfield a scarcely deserved 1-1 draw at Cambridge.
A poor Louis Appere clearance found McFadzean, who fired powerfully past the unsighted Jake Eastwood from the edge of the box.
Chesterfield boss Paul Cook was booked for arguing inside three minutes and his evening got worse 10 minutes later when Glenn McConnell’s corner from the left was powered home by the head of Kell Watts.
After 53 minutes Korey Smith’s low shot was kept out by the fingertips of Zach Hemming.
Having offered very little, the Spireites were almost level on 66 minutes when Eastwood made an excellent save to push away Dylan Duffy’s shot from 20 yards.
Pushing for an equaliser, they were presented with an opening 10 minutes from the end when Liam Bennett gifted the ball to Ronan Darcy, who could only blast over.
At the other end substitute Appere was denied by Hemming, then Liam Mandeville did brilliantly to block Smith’s shot on the line, allowing McFadzean to snatch a point.
