Hartlepool United were denied a fourth away win of the season by a last-minute Ben Williamson equaliser.
Pools had deserved their lead 19 minutes from time when Jake Gray scored his fourth goal of the season.
Ronnie Moore's side defended well but with normal time almost up, Williamson got on the end of a long ball from the back to beat Trevor Carson to end the U's five and a half-hour goal drought.
Cambridge: Norris, Furlong, Legge, Roberts, Page, Dunne, Ledson (Donaldson 71), Berry, Simpson, Ahearne-Grant (Dunk 54), Williamson.
Unused subs: Beasant, Omozusi, Coulson, Horne
Goal: Williamson 90
Pools: Carson, Richards, Bates, Jackson, Carroll, Featherstone, Woods, Gray, Hawkins, Oates (Jones 90), E Harrison (Bingham 34).
Unused Subs: Bartlett, Thomas, Walker, Smith, Fenwick
Goal: Gray 71
Referee: Keith Hill
Att: 5.054 (Pools 186)
Cambridge had the first chance when Robbie Simpson found Karlan Ahearne-Grant who fired very wide from the edge of the area in the second minute.
Pools though quickly took charge and had a succession of chances.
A fifth-minute Jake Carroll free-kick found Ellis Harrison who was unlucky to hit the post with keeper Will Norris fortunate to, eventually, gather the ball following an almighty scramble.
Three minutes later, Pools came forward and Harrison had a left-foot shot from the edge of the box blocked by Leon Legge.
Norris saved the U's in the 10th minute with a great double block, first keeping out Harrison and then Jake Gray's follow-up.
Cambridge did come into the game as the match wore on and had plenty of pressure, but the only threat to the away goal was a looping header which Trevor Carson collected with ease.
Pools suffered a blow 11minutes from the break, hobbling off after being hurt in a collision with Lewis Page.
Pools had two early chances at the start of the second half and were denied twice by Norris.
Michael Woods put the attacking midfielder through but the keeper came out well to save.
And shortly afterwards, the Crystal Palace prospect had another opportunity but Norris pushed the shot away to his right.
Pools had a decent spell just before the hour-mark with Lewis Hawkions having a half-chance go well wide.
U's boss Shaun Derry made two changes bringing on Harrison Dunk, who scored the winner in this match last season, and star striker Barry Corr.
Cambridge threatened in the 64th minute when Carroll made a good block from Luke Berry.
Pools finally got the breakthrough in the 71st minute.
Woods threaded the ball through to GRAY whose shot from 12 yards seemed to have been saved by Norris buty he could not keep the ball out.
Cambridge had their best chance 15 minutes from time but skipper Roberts headed wide from seven yards.
The U's had some late pressure but Carroll made a good block on Corr with three minutes to go.
Pools were denied in the final minute when Jackson could not cut out a long ball from Legge and WILLIAMSON beat Carson from close range.
CAMBRIDGE UTD 1
HARTLEPOOL UTD 1