Daniel Chillingworth hit a hat-trick as Cambridge destroyed Weymouth.
Dan Gleeson stabbed in from six yards to put the home side ahead before Chillingworth thumped in a header and scored with a dipping volley.
Robbie Simpson bagged a brace with two well struck shots and Chillingworth completed his hat-trick when he slid in to convert a Courtney Pitt cross.
Stephen Smith completed the club-record rout with a strike from 15 yards as Cambridge boosted their survival hopes.
Cambridge Utd: Crichton, Morrison, Peters, Aidan Collins, Gleeson, Stephen Smith, Brown, Wolleaston, Pitt (Jordan Collins 80), Chillingworth (Purser 70), Robbie Simpson (Hughes 66).
Subs Not Used: Herbert, Bridges.
Booked: Peters, Brown, Pitt.
Goals: Gleeson 6, Chillingworth 10, 18, Robbie Simpson 38, 64, Chillingworth 69, Stephen Smith 82.
Weymouth: Matthews, Vickers (Dutton 57), James, Cottrell, Crittenden, Coutts (Tindall 68), Robinson, Weatherstone, Welsh, Nade (Phillips 32), Beavon.
Subs Not Used: Bell, Platt.
Ref: S Beck (Essex).