Cambridge stunned promotion-chasing Bury with a comprehensive 3-0 win at Gigg Lane.
Alex Jones, David Amoo and George Maris were on target as the U's eased their relegation fears with a first win in five games, while the hosts crashed to a second home defeat in four days.
Bury, who lost their first league game in 15 at the weekend, struggled again in the first half against the previously out-of-form U's.
Jones fired the visitors ahead after 16 minutes, slotting home low past Joe Murphy after Jevani Brown's initial shot had been blocked.
The lead was doubled in the 34th minute as ex-Bury loanee Amoo latched on to Brown's precise through-ball before drilling confidently past Murphy.
The hosts almost halved the deficit just before the break when Nicky Maynard forced a fine low stop from U's goalkeeper Dimitar Mitov.
Amoo had the ball in the back of the Bury net again in the 50th minute, but he had pounced from an offside position.
But Cambridge did score a deserved third in the 72nd minute when Maris side-footed neatly into the net after a corner from Brown was not cleared.