Shay McCartan fired home his fourth goal in three games to keep Accrington's slim Sky Bet League Two play-off hopes alive and hurt Cambridge's in a 2-0 win.
Stanley made it 11 games unbeaten as Sean McConville and McCartan scored the vital goals to move them into 13th place, seven points off the top seven and two behind Cambridge.
Stanley took the lead in the 19th minute when Cambridge failed to clear their lines and Jordan Clark set up McConville in the area and he rifled home his sixth goal of the season.
McConville came close to a second three minutes later but, unmarked at the far post, his effort was saved by goalkeeper Will Norris.
Cambridge's main threat was 17-goal top scorer Luke Berry and he carved out a number of chances, heading wide, having an effort blocked on the line and forcing Aaron Chapman into a good save.
But McCartan celebrated his ninth goal of the season after 54 minutes when Billy Kee's pass sent him racing free and the striker held his nerve to fire beyond Norris.
Stanley could have had more with both McConville and McCartan missing superb chances.