Sammie Szmodics struck a late equaliser to earn Colchester a 1-1 draw at Cambridge in Sky Bet League Two.
Substitute Szmodics turned home from close range six minutes from time after good work on the left by Ben Dickenson, moments after Macauley Bonne had seen a goal disallowed for offside following another Dickenson cross.
Gerry McDonagh had earlier scored his first EFL goal to give the home side the lead after 20 minutes, thumping the ball home following George Maris' ball from the right.
Cambridge also had a goal disallowed when Harrison Dunk fired in following Piero Mingoia's cross 11 minutes before half-time.
Colchester's only real opportunity of the first period came in the opening moments when Dickenson could only nod Owen Garvan's cross wide at the far post.
John McGreal's side were denied 17 minutes from the end as a superb save from Will Norris kept out George Elokobi, before McDonagh fired narrowly wide at the other end ahead of Szmodics' equaliser.