Crawley Town's Barry Cogan scored the winner as Cambridge United suffered a sixth consecutive defeat at the Broadfield Stadium.
Cogan fired past Laurie Walker and into the bottom corner to earn his side an eighth-minute lead.
Home striker Charles Ademeno should then have made it two when heading wide from six-yards out.
At the opposite end, Robbie Willmott couldn't find his way past Red Devils keeper Simon Rayner.
Crawley Town: Rayner, Rusk, Quinn, Broadhurst, Rents, Cogan, Hutchinson, Smith (Forrest 82), Pinault, Ademeno (King 90), Malcolm (Killeen 88)
subs (unused): Jordan, Lake-Edwards
Goals: Cogan (8)
Cambridge United: Walker, Gleeson, Palmer, Coulson, Partridge, Reason, Russell, Ives (Murray 73), Willmott, Crow (Marriott 82), Phillips (Beesley 70)
subs (unused): McAuley, Coakley
Ref: M. Bull (Essex)
Att: 1,108





