Chelsea FC returned to winning ways as their defence of the UEFA Champions League title began in earnest, though the scoreline was harsh on competition newcomers FC Nordsjælland who played with heart and skill throughout.
Only three goals inside the last 11 minutes allowed the Londoners to breathe easily at a job well done. Juan Mata added to his first-half effort shortly after David Luiz had converted a free-kick, and while Ramires also got in on the act, the Danish champions had come close to equalising before the late rush.
Initially it looked as if Nordsjælland might freeze on their big night as the ball was given away in dangerous areas, with Chelsea seemingly more alive to every situation. It should have led to an early breakthrough, but somehow the hosts' goal remained intact for the first half-hour.
In the fourth minute Oscar's flighted ball from the right was met first by Jores Okore, who headed against his own post nanoseconds before Victor Moses, making his competition debut, arrived on the scene. The clash of heads necessitated lengthy treatment for the Nordsjælland defender.
Fernando Torres and Frank Lampard could not take advantage of openings, spurring Kasper Hjulmand's side into offering more themselves – their composure in possession spreading the belief that they did not have to be bystanders in a Chelsea exhibition. Ashley Cole's loose pass across the pitch invited Joshua John to unleash a wayward shot which at least signalled the home team's intent. A dangerous John cross then required Cole to make a crucial block.
At the other end, though, the first goal was a reward for Torres's endeavours as he robbed Enoch Adu and fed Lampard, who set up Mata for a clinical finish. Nordsjælland refused to let the setback undermine their efforts and even before the goal their willingness to flood the Chelsea area with red shirts spoke volumes for their spirit.
Striker John led the attempted fightback, cutting inside but firing just the wrong side of the upright. Better openings fell to Mikkel Beckmann yet he was off target. Nordsjælland came closest of all in the 73rd minute when John repeated his earlier incursion, Petr Čech tipping the drive onto a post. Beckmann's follow-up might also have gone in but Cole was in the way.
The late flurry finally began with Luiz crashing in a direct free-kick, while Mata's second followed a series of neat passes. Oscar's vision laid the fourth on a plate for compatriot Ramires.