Juan Mata scored twice as the Blues won their first Champions’ League group match of the season.
Further goals from David Luiz and a late goal Ramires secured three Group E points which puts the Londoners top of the pile.
Mata’s opener came courtesy of good set-up play by Fernando Torres and Frank Lampard. David Luiz converted from a free-kick before Mata struck with a left-footed drive.
Ramires goal, in the 89th minute, gave the impression of a rout, but in truth the home side could have equalised on several occasions.
Lampard was restored to the starting line-up and John Terry relegated to the bench.
Next up for the Londoners is a potential banana skin when the Blues play away to Shakhtar Donetsk on Tuesday, October 23.
Teams: FC Nordsjaelland
Hansen Okore Mtiliga Parkhurst Runje Adu Stokholm Beckmann (Christensen - 75' ) Lorentzen (Laudrup - 84' ) Nordstrand (Ticinovic - 65' ) John
Substitutes: Villadsen Christiansen Christensen Gundelach Laudrup Petry Andersen Ticinovic
Chelsea: Cech Ivanovic Cole David Luiz Cahill Ramires Lampard Mata (Mikel - 83' ) Oscar Moses (Hazard - 65' ) Torres
Substitutes: Turnbull Terry Azpilicueta Bertrand Romeu Mikel Hazard
Ref: Strahonja
Att: 42,000