George Maris scored the only goal of the game as Cambridge claimed a 1-0 win against struggling Barnet.
Jevani Brown's quick feet on the edge of the box allowed him to play in Maris, who calmly slotted beyond substitute goalkeeper Craig Ross in the 62nd minute.
The U's had gone closest early on, with Ade Azeez firing straight at Jamie Stephens and Greg Taylor shooting fractionally wide after a set piece was not cleared.
Barnet should have broken the deadlock six minutes before half-time but John Akinde could only lift the ball over the crossbar when through on goal.
In the final moments of the half Azeez wasted a golden chance when he pounced on a poor back-pass but could only fire straight at substitute keeper Craig Ross.
Seven minutes after the interval Brown could only head straight at Ross from close range following David Amoo's cross, but he made amends by creating the goal for Maris.
Looking for an equaliser, Barnet striker Simeon Akinola forced David Forde into a good save 20 minutes from the end following Akinde's pass.