Two goals from Mata, David Luiz's free-kick and Ramires late tap-in give Chelsea a slightly flattering scoreline in Group E but they will be happy with the three points. Nordsjaelland's deficiencies as European minnows were ultimately exposed as their defensive errors and failure to take their chances were exposed. Stay with us for all the post-match reaction, including the match report, player ratings and quotes.
90 + 3
FULL-TIME: NORDSJAELLND 0 CHELSEA 4
90 + 2
Chelsea, though, enjoy a good period of possession as they run down the clock.
90 + 1
Nordsjaelland's fans have not lost heart and continue to sing in injury time. Their team are still attempting to pass but are not really getting anywhere.
The scoreline now flatters Chelsea a little but it is a nice goal from the defending champions. Torres feeds Oscar, who has been quiet tonight, and the Brazilian toe pokes a short-range cross from the byline to Ramires and his compatriot taps in.
GOAL RAMIRES (0-4)!!!
Mata's two goals make him man of the match tonight. But special mention should also go to Okore for his defending and passing.
Torres will be a little frustrated he has not, as yet, got on the scoresheet. He has got through a lot of work for his team tonight.
Nordsjaelland have not given up and Stokholm sprays a pass out to the right for the ever-willing run of Parkhurst. But Ivanovic intercepts.
Chelsea are not finished and are still attacking. Lampard takes a shot on the run from the corner of the box but hits it over the top of Hansen's goal. Lampard has his hands up to apologise to his team-mates.
Laudrup, son of Swansea City manager Michael, comes on in place of Lorentzen.
The goal was Mata's last contribution as he is replaced by Mikel.
To rub salt in my wounds after my earlier criticism, Mata has his second goal of the night. The ball ricochets to the Spaniard inside the penalty area and he shows great control and reflexes to hit a low finish into the back of the net. Harsh on Nordsjaelland but they have been guilty of bad defending and not taking their chances.
GOAL MATA (0-3)!!!
That should be game over. Nordsjaelland deserve credit for their attitude and effort tonight. But, unless something remarkable happens, they are going to be losing.
From the free-kick, Luiz smacks in a direct effort from 25 yards which goes into the back of the net off the near post. Luiz hit the ball in the style of Cristiano Ronaldo with his laces to give it some dip and swerve.
GOAL LUIZ (0-2)!!!
Chelsea seem to have decided they need to exert a bit of pressure and are keeping Nordsjaelland in their half. Torres wins a free-kick 25 yards from goal.
Lampard takes the free-kick and blasts it into Nordsjaelland's vast wall. That is a bit of a waste but Lampard did not have many other options.
A very clumsy and reckless challenge from Runje on the edge of the Nordsjaelland box earns a booking and a free-kick.
Chelsea have looked so lethargic in the second half and that John effort was a big warning.
Beckmann, who did not have the best of games, is off and Christensen comes on.
Great save from Cech! John cut in from the left and hit a goal-bound right foot effort. It is heading for the top corner from 18 yards but Cech just manages to get a fingertip to the ball and push it onto the post and away. Chelsea are riding their luck. Cole blocks a follow-up effort.
An overlapping run down the right sees Parkhurst charge into the penalty area. Cech, though, is aware of the danger and sprints off his line to slide and collect the ball before the full-back.
Di Matteo is stood on the edge of his technical area and is waving his team forward. He knows they are playing a risky game at the moment and are inviting pressure from Nordsjaelland.
Beckmann plays a decent ball behind the back of the Chelsea defence. But Adu has made a different run and the move therefore comes to nothing.
Nordsjaelland are still attacking their visitors. Chelsea are looking strangely sluggish.
Di Matteo will be hoping Hazard will bring a bit of spark to Chelsea. After blowing a two-goal lead against Juventus, Chelsea are always running the risk of conceding an equaliser tonight.
Break in play as referee Strahonja tells Stokholm to leave the pitch in order to put his boot back on after it came off in a challenge with Mata.
There is a strange feel to this match. It seems very flat at the moment and does not really have the feel of a Champions League game. Whether or not Nordsjaelland are minnows to Chelsea's kings of Europe, there is not that great a gulf in class.
As Beckmann hits another effort wide, both teams use the break in play to make changes. Ticinovic is on for Nordstrand. Chelsea replaces Moses with Hazard.
Okore makes a bit of a hash of dealing with a cross. He only smacks the ball high up into the air and will have been grateful to see Hansen catch it.
John is frustrated to be flagged offside but replays show it was the correct decision.
Stokholm shows Cahill how to shoot from long-range as his swerving right-foot effort has to be palmed away by Cech.
Cahill goes forward and tries his luck from 25 yards. But the centre-back is high and wide with his effort.
Chelsea have seemed a slightly laid back in the second half. They are in danger of becoming complacent.
Now Okore strides out of the centre of defence. He is given far too much room by Chelsea and picks a perfect cross for Beckmann. However, the striker heads horribly over the crossbar.
Lampard bursts forward and plays a give-and-go with Oscar as he rolls back the years with one of his runs into the penalty area. But he is tackled by the excellent Okore.
Suddenly Nordsjaelland have an extra man in a four-on-three attack. But they do not seem to realise and Lorentzen takes all the pace out of the break, allowing Chelsea to get back.
An eye-of-the-needle pass finds Torres in the penalty area. But he is sandwiched by Okore and Parkhurst before being tackled inside the area by the former.
Nordsjaelland have not changed their strategy despite the manner of the goal they conceded in the first half. They are still passing the ball out of defence and their moves usually start with Okore.
Now Moses has the ball in the back of the net but it does not count due to a foul in the build-up. Replays show Moses pulled back Parkhurst when racing for Torres' pass.
John manages to keep the pressure on Chelsea and he cuts in from the left and hits a low shot which whistles just past the near post.
Free-kick to Nordsjaelland deep in Chelsea territory and it is a chance to send the ball into the box. Lorentzen's delivery is poor and does not beat the first man, Mata, who heads clear.
Nordsjaelland do not clear the ball very far and Chelsea win another corner. Mata's delivery causes problems and two defenders miss the ball and are lucky no Chelsea player reacts.
A volleyed pass out to the left from Lampard to Moses results in a corner to Chelsea. From the set-piece Hansen flaps a little but just gets a touch to prevent Ivanovic from surely scoring Chelsea's second goal.
Nordstrand plays a ball through the centre of the Chelsea defence and looking for John. Cahill, though, has covered the run and can defend.
Lovely build-up from Chelsea as they pass out from the back before Torres can break the offside trap. But Hansen is off his line quickly to again block the striker's shot with his legs.
Nordsjaelland start where they left off. Okore overplays at the back and Torres can get the ball. The home side are relieved to see a referee's assistant's flag raised.
Neither side have made any substitutions at half-time and at an early look they are still both playing in 4-2-3-1 formations.
WE'RE BACK: Nordsjaelland get the second half under way.
Willie Maher says: "I think this game is set up nicely for Torres. He's causing all sorts of problems and I think he'll be rewarded with a second-half brace."
Mata's 33rd minute goal gives Chelsea a 1-0 lead at the break. Nordsjaelland played some nice stuff but also caused their own problems. It looks like there will be more goals in this for Chelsea. Nordsjaelland's best attacking outlet has been Lorentzen. But he has been very well defended by Cole. Torres is working very hard, closing down opponents, up front for Chelsea and looks a threat. He has had one good chance saved by Hansen. Let me have your thoughts on the first half at email@example.com or via Twitter @SkySportsPeteF.
45 + 1
HALF-TIME: NORDSJAELLAND 0 CHELSEA 1
ADDED TIME: There will be a minimum of one minute added time before half-time.
Torres has the ball in the back of the net from a hooked Ivanovic shot, which was probably going out for a throw-in. But Torres knows he is a long way offside and does not celebrate.
Okore has probably been Nordsjaelland's best player in the first half. From his earlier header, this time he shows great pace to get back and tackle Moses.
Hansen and Okore exchange passes to the right of the penalty area but invite pressure from Torres and Oscar. Okore decides to take no chances this time and thumps the ball down the line and into the Chelsea half.
Chelsea are now just looking towards half-time. Ramires is dropping very deep to take the ball off Luiz and Cahill and keep the passing game going.
Mtiliga's skidding effort tests the handling of Cech from 20 yards. The experienced Chelsea goalkeeper is up to the task when diving low to his left to gather the ball.
Nordsjaelland win another corner. It is again played short before John curls the ball into the box. Cahill heads away the danger and Cole prevents the ball from going for another corner.
Moses is having a good evening for Chelsea. He is having to do a lot of running back towards his own goal.
Nordsjaelland really are playing a high-risk strategy and again almost gift Chelsea a goal before Oscar is closed down inside the penalty area.
Torres continues to push right onto the last defender and is occupying both centre-backs this evening. He did very well when taking the ball off midfielder Adu in the build-up to the goal.
Nordsjaelland now have to chase the game, which will be perfect for the way Chelsea are set up to hit their hosts on the counter-attack. Cruel on Nordsjaelland to go a goal down but they did self-destruct.
So after I had been critical of Mata, he puts Chelsea in front! Nordsjaelland played themselves into trouble when attempting to pass out from defence. They had been threatening to do that. Torres robbed Adu before Lampard set up the overlapping Mata for a finish through the legs of Hansen from around 10 yards down the inside right channel.
GOAL MATA (0-1)!!!
More good defending from Cole as he slides a challenge to beat Lorentzen to the ball. Cole then races up field and wins a throw-in close to the corner flag off Okore. Fantastic, trademark energy from the Chelsea left-back.
Mata curls the corner towards the near post. But John attacks the set-piece and gets commanding header to fly high up the field and away from danger.
Adu sees a shot blocked from outside the Chelsea penalty area and the Premier League club break up field to win a corner.
The possession is now 50-50. But Nordsjaelland have completed 157 passes to Chelsea's 134.
Nordsjaelland are not defending high up the pitch. They are happy to let Chelsea have the ball at the back before squeezing their opponents. That means Chelsea are now having to look to long balls. Luiz attempts another cross-field pass but hits it out of play.
Mata's frustration at his failure to influence the match is clear. He gives away a free-kick for pulling back Nordsjaelland captain Stokholm.
Luiz attempts to stretch play with a cross-field pass towards Oscar. But Mtiliga reads the ball and intercepts.
Excellent pressing from Nordsjaelland sees a potential Chelsea attack through Torres eventually forced all the way back to Cech.
Not it is Chelsea producing the unforced errors at the back as Cahill fails to control a ball and it rolls out for a throw-in to Nordsjaelland in the Chelsea half.
Nordsjaelland's fans are enjoying their team's performance and are cheering every pass from their side.
Chelsea break up field and Torres manages to get a shot off from 18 yards after allowing the ball to drop from a poor defensive header from Nordsjaelland. Hansen stays on his feet and blocks with his shins.
Lorentzen is making some could runs toward the back post from his position on the right wing. Cole is having to do a lot of tracking back.
Typically alert defending from Cole as he just manages to beat Lorentzen to a dangerous ball towards the Chelsea box.
Nordsjaelland are currently shading the possession stats with 53 per cent. Chelsea are struggling to get Mata into the game and could do with the Spaniard's influence.
It is admirable how Nordsjaelland are playing their way out from the back. Whenever the ball is with goalkeeper Hansen, it is played out to full-backs rather than going long. The Danish champions are growing in confidence after their nervy start.
Hjulmand's team do not make the most of the set-piece. It is played short before being sent into the box and a man over at the back post is wasted as Cech claims the cross.
Corner to Nordsjaelland after Cahill has to slide to block a Nordstrand shot. The effort was heading towards goal.
The home side remain on the attack but John, clearly full of confidence from his eight-goal scoring running, blazes a wild right-foot effort well over the crossbar from 20 yards.
Nordsjaelland enjoy a good passage of play and enjoy a bit of possession on the edge of the Chelsea box. Beckmann almost connects with a cross from the left.
Nordsjaelland are sticking to their principles. They are refusing to launch long balls down the field. But they are at times playing themselves into trouble from the back.
This could be a long night for Beckmann. He is the lone striker for Nordsjaelland and is very isolated. He is having to do a lot of chasing of the passing of Chelsea defenders and after just 12 minutes already looks like he is feeling the pace.
Okore is applauded back onto the pitch with a bandaged head. He is immediately required to tackle Torres and then outpace the striker to clear.
Ivanovic tees up Lampard for a right side-foot effort from 18 yards. But the midfielder just gets a little under the ball and scoops it over the crossbar.
Things open up for Torres on the edge of the Nordsjaelland box after Parkhurst cannons an attempted clearance into Moses. But Torres overruns the ball and leaves it behind before being tackled inside the penalty area.
Both teams are lined up as 4-2-3-1 tonight, which means central midfield is a little congested. Moses looks like he could be a good outlet down the left for Chelsea.
Nordsjaelland are still playing with 10 men at the moment as Okore remains on the sidelines and is getting the stiches to the cut above is right eye.
Chance for Chelsea to send a crossed free-kick into the box after Cole is pulled back. But the set-piece is wasted.
Chelsea have started with a clear intent to get an early goal to crush any early impetus from Nordsjaelland.
Okore put his body on the line to save his team from that chance. He has had to leave the pitch to have some stiches to a cut on his forehead.
Great chance for Moses at the back post. From Oscar's dinked cross, it looks as if Moses is certain to score. But Okore defends superbly to get his head to the ball and take a whack in the process.
Nordsjaelland are all over the place at the back and a combination of Torres, Oscar and Moses almost force a breakthrough from a poor throw-in. Nordsjaelland look nervous.
Cech takes an early risk with a heavy touch when dealing with a back-pass which almost sees Beckmann pinch the ball.
KICK-OFF: Chelsea get the game going.
Here come the teams. Respective captains Sokholm and Lampard lead out Nordsjaelland and Chelsea at Parken stadium.
OPTA FACT: All three of Nordsjaelland's shots in their opening defeat by Shakhtar Donetsk hit the target. They also picked up a joint-high five yellow cards on Match Day One.
Chelsea's lack of strikers is highlighted again tonight. With Sturridge having not travelled due to his hamstring injury, Di Matteo has no recognised striker on his bench.
Di Matteo pre-match TV interview: "We have to be focused and try to win this game."
Alee says: "For this particular match, I fear there's an over confidence among the Chelsea side and the opponents can come up with an expected strategy. My personal prediction is a 1-0 away win, with an 89th minute goal scored by Lampard from a penalty."
Could Roberto Di Matteo's decision to rest Terry on the bench be with an eye to the centre-back's looming domestic ban? Chelsea will need Luiz and Cahill to be well aquatinted. Let me have your thoughts at firstname.lastname@example.org or via Twitter @SkySportsPeteF.
Chelsea are 4/9 to win tonight with Sky Bet while a huge upset and a Nordsjaelland victory is 13/2. If you reckon Torres will score first, the Spaniard is available at a price boost on 7/2.
OPTA FACT: Chelsea's last meeting with a Danish team came in the 2010/11 round of 16 when they won 2-0 away and secured progress to the next round with a 0-0 draw at home to Copenhagen.
Akshet says: "Good to see Hazard is getting a rest. Good for the team and himself. Hopefully Oscar can score another wonder goal."
The Laudrup in coach Kasper Hjulmand's Nordsjaelland squad is 21-year-old Andreas. He is the son of Danish legend and Swansea City manager Michael Laudrup.
This would be a genuine giant-killing if reigning European champions Chelsea suffered any sort of upset at Parken in Copenhagen tonight. But do not forget Chelsea did not win any of their away games in last season's group stages.
Joe Manifold says: "Expecting Chelsea to win but not without conceding. 3-1 to Chelsea, Torres to score twice with Lampard scoring as well, no particular order. Come on you Blues!"
Sam Montgomery says: "Don't know why me have both Romeu and Mikel on the bench, but going for Chelsea to win 3-0."
Ashwin Iyer says: "It's a good move to rest the likes of Hazard and Mikel because Moses has been performing well in all his cameos."
Nordsjaelland's danger man is Joshua John. The on-loan FC Twente striker has scored eight goals since making the move to Denmark. Nordsjaelland are the defending Danish champions and won 3-0 against Esbjerg on Friday.
Referee: M Strahonja (Cro). Assistant referees: S Premuzaj and I Krmar (Cro). Fourth official: I Modric (Cro)
You can have your say on the team selections, offer your predictions and any other views you might have throughout the evening. Join the debate by dropping me a line at email@example.com or via Twitter @SkySportsPeteF. I will publish a selection of the best comments.
Here's a round-up of the team news. Frank Lampard returns to captain Chelsea as John Terry is rested on the bench among three changes to the team who beat Arsenal. Lampard makes his first start since the Group E draw against Juventus, with Gary Cahill replacing Terry and Victor Moses coming in for Eden Hazard. Danish champions Nordsjaelland's only change for arguably the biggest match in their history sees fit-again forward Mikkel Beckmann recalled.
Chelsea team: Cech, Cole, Luiz, Cahill, Ivanovic, Ramires, Lampard, Oscar, Torres, Mata, Moses. Subs: Turnbull, Terry, Azpilicueta, Bertrand, Romeu, Mikel, Hazard.
Nordsjaelland team: Hansen, Okore, Mtiliga, Parkhurst, Runje, Adu, Stokholm, Lorentzen, Beckmann, Nordstrand, John. Subs: Villadsen, Gundelach, Christensen, Ticinovic, Petry, Christiansen, Laudrup.
Hello and welcome to our live and interactive coverage of Chelsea's UEFA Champions League Group E meeting with Nordsjaelland in Denmark. Stay with us for full team news.