Wrexham were the more dominant side right from the off and could have taken an early lead Ryan Barnett was brought down inside the Cambridge box by James Brophy, however, the referee decided to continue play without awarding the hosts a spot-kick.
The visitors finally broke the deadlock against the run of play when Elias Kachunga received Shayne Lavery's cross and slotted past Mark Howard in the 20th minute. Their celebrations, however, didn't last long as Wrexham restored parity after just seven minutes courtesy of James McClean's strike. Barnett kept an inch-perfect cross inside the box which McClean comfortably slotted home with a clinical header.
While the Red Dragons did dominate proceedings in the first 45 minutes, they committed too many mistakes which at times allowed Cambridge to pose a threat in front of their goal. The hosts finally took the lead after the break in the 65th minute when Oliver Rathbone snatched the ball away from an opposition player before setting up second half substitute Steven Fletcher with a perfect pass who comfortably found the back of the net.
Just when it seemed that the Welsh side would wrap up the clash with yet another win, Lewis Brunt committed a terrible mistake by pulling down Sullay Kaikai inside the box and Dan Nlundulu netted the equaliser from the penalty spot.