Wrap: So, as weeks go, that one's been an absolute shocker for United. Ferguson will be fuming, and quite rightly, with Chelsea's winner, which was two yards offside, but he'll be even more concerned about how flat his team looked. At the time of the year when champions are meant to kick on, United look jaded mentally, as well as physically and a pessimist will conclude that Rooney's injury has wrecked their chances of success in two competitions. Chelsea go two points clear, and after beating Villa and United in succession they must be considered fairly strong title favourites now. Thanks for ignoring 3-D, and join us again for next week's Champions League action.
From Henry Winter at Old Trafford: "United better 2nd half but Chelsea deserve win. More belief, more nous. Big moment in title race. Force with Chelsea."
90+ 3: Nani wins a free kick after clashing with Ferreira, but Chelsea cope with it easily. United unable to build up a head of stream here.
90 min: Berbatov volleys straight at Cech from Neville's cross. That's a pretty good chance, didn't have to break his stride to hit the ball, but his contact is poor and it bounces up into Cech's midriff. We've got four minutes of Fergie time.
88 min: Chelsea dropping deep now, to play out the clock. Wonder what Fergie time, we'll get. An hour?
85 min: United's final throw of the dice Gibson on for Fletcher.
84 min: Malouda cuts inside from the left flank and feeds Lampard, who, given the amount of space and time he had, should have done better than a shot that flashed wide of Van der Sar's right post. Fletcher's booked by Mike Dean as the temperature cranks up another notch.
81 min: GOAL! Man United 1-Chelsea 2 United level through Federico Macheda. And we may just have a game on here, y'know! Macheda knew very little about the goal, with Nani's cross from the left wing appearing to strike him on the chest as Cech watched the ball loop over the line.
78 min: GOAL! Man United 0-2 Chelsea United's mini-recovery is nipped in the bud by Didier Drogba. He is blatantly offside when peeling off of Vidic to collect Kalou's short through ball, but he smashes it past Van der Sar with fearsome power.
76 min: Terry's measured pass inside Neville puts Zhirkov into space but his cross just evades Drogba and rolls across the United goal to safety.
74 min: United are beginning to peg back Chelsea, without, it must be said, playing particularly well.
72 min: Change for United as Scholes comes off for Nani. Macheda has also replaced Park, and Cole is coming off for Kalou too.
70 min: Yellow card for Deco now, for a fairly tame clip on Lampard. Neville and Scholes, who've both been carded, are ticking here, and they've both been warned by Mike Dean that they're walking a tightrope.
66 min: Berbatov on the end of another cross, but this time is header flashes over the bar. United are having considerable joy down the Chelsea left, and Malouda really needs to drop back and assist Zhirkov, who is being overrun. Drogba warming up now. straight swap for Anelka.
62 min: Cech can't grab hold of a deep Evra cross, but with the goalkeeper flapping Park can't quite take advantage as he tries to steer the looping centre back towards goal.
59 min: United finally get the crowd going. Excellent spell of pressure started by Berbatov and Giggs stretches Chelsea. Valencia's cross eventually finds Berbatov at the far post but his header's wide. Better though, at long last.
55 min: Decent free kick opportunity for United after Cole catches Park. They lack a right-sided free kick taker though, United, and Giggs end up chipping it towards Berbatov, who slips over in the box. Not great.
53 min: Scholes picks out Valencia on the right touchline, but Zhirkov successfully shifts him inside onto his left foot. Valencia crosses deep where Evra's lurking, but his first-time volley is harmlessly wide.
50 min: Better start from United, this half, with both Neville and Evra involved in the Chelsea half. Chelsea are dropping very deep though, and still look pretty solid.
48 min: Ferreira's a yard away from doubling Chelsea's lead. Another clever flick from Joe Cole plays in Ferreira, but under pressure from Evra he can only stab his right-foot shot wide.
46 min: No changes for either side. Can't be long for United, should it stay like this.
45+2 min: HT: Man United 0-1 Chelsea. Far too easy that, for Chelsea.
WRAP: Even despite Carlo Ancelotti's kind pre-match gesture ("Your best player's injured, so I'll leave mine on the bench too") the three-time champions have been comfortably mastered by Chelsea today. Chelsea haven't been great Van der Sar's hardly had a save to make but they've been good enough, dominating possession and making United look very disjointed. They scored from the game's one moment of true quality, and United will be looking for some legs from the bench. Nani? Macheda? Not overly exciting options, especially considering the ammunition Ancelotti can call on. OK, teams are back out.
Alex Ferguson, in today's match programme: "I'm glad we kept faith with Berbatov because he's really showing his true worth on a regular basis now".
43 min: Superb tackle from Lampard denies Berbatov. There are throaty screams for a United penalty, but Lampard's tackle while risky was perfectly executed. Less good, however, is Neville's hack on Malouda, for which he's rightly booked.
40 min: Anelka and Deco combine well, again, in the Chelsea midfield. United's frustration is evident when Vidic leaves his post to flatten Anelka from behind. Ferguson will have to change this at half-time, you'd have thought.
34 min : Scholes is booked for a typically Scholesian lunge on Malouda, who avoided a real clattering by hurdling the 'tackle'. Still Chelsea who're dictating this game, and having scored the early goal, they're more than happy. Deco is particularly enjoying the measured pace of the game, picking out his passes beautifully.
31 min: Penalty appeal at the other end now, as Anelka goes down under Neville's challenge. Nothing doing again though, with Mike Dean apparently desperate to stay out of the headlines today. Very clumsy from Neville, on the replay, barging in from the side and not winning the ball. Limited appeals from Chelsea's players.
26 min: Penalty shout from United as Park tumbles over Zhirkov's leg. Mike Dean's not interested, but the replay shows does show some contact there. Alan Green on 5 live is screaming for Park to be booked for a dive you can draw your own conclusions from that. I'd say Zhirkov's a little lucky there, but if Dean thought it wasn't a penalty, then a card should have followed.
24 min: No signs of a response from United. Unsurprisingly, they're missing him. United have 20 minutes to avoid a serious talking to.
19 min: GOAL! Man United 0-1 Chelsea And Chelsea take the lead through Joe Cole. Cheeky flicked finish with the inside of his left heel. Lovely touch following a brilliant, direct run from Malouda. Bang in form, is the Frenchman, and his burst was the first of the afternoon to put a defence on the back foot. Showed good strength to hold off Fletcher near the touchline, and then darted into the space as Neville was distracted by the overlapping run of Zhirkov. Once Malouda reached the byline, he crossed to Cole on the edge of the six-yard box who did the rest with some style. Really poor start from United.
17 min: Hmm. Cagey. And not that kind of interesting tactical cagey, but just two teams who seems pretty happy with a 0-0.
13 min: Better from United as Evra and Giggs trade passes. Evra takes on Alex, and without anyone to cross toward, opts to shoot at Cech but his effort lacks a bit of zip.
12 min: Scrappy. United look a little jaded. Strange mistakes from Fletcher and Scholes.
8 min: Cautious stuff in midfield. Anelka is dropping deep, which gives Chelsea the numbers in midfield, but United are comfortable letting the visitors play in front of them.
4 min: Wonderful run down the left flank from Berba, spins past Ferreira with cracking little trick but his stabbed cross is cut out.
3 min: Giggs has started on the left, with Park playing off Berbatov. Looks like Park's been asked to do the Bulgarian's running, poor guy. Bright start from Chelsea, with Lampard seeing plenty of the ball already.
1 min: Chelsea get in the afternoon's first dig Deco slapping a shot wide of the post after a lively run from Malouda.
12.43: OK, handshakes over, we're under way.
12.38: United will be looking for Valencia to get at Zhirkov, whose defensive credentials aren't quite as well established as his attacking abilities. Malouda against Gary Neville could be Chelsea's banker.
12.30: David Haye, who fights John Ruiz down the road tonight, is out in the middle at Old Trafford, doing that clenched fist pose thing that boxers seem to do all the time. Did Sky do a "knockout blow in the title race" pun? What do you think?
12.25: Significant afternoon in the career of Dimitar Ivanov Berbatov. I could tell you why, but I think it's more fitting, more 'Berba', if I just point a elegantly weary finger in the direction of Alan Smith's preview.
12.20: Live in 3-D this one, today. But as you're obviously not in front of a TV, I'll not mention that again. Much, much, better off here.
12.15: So no Drogba then, for Chelsea. Didn't exactly reduce their attacking potency last time out, of course. But after he was officially passed fit on Thursday, that's something of a surprise. Amazing if he's been dropped, but I guess you can make a fairly strong case to keep faith with a team that spanked Aston Villa 7-1.
OK, teams are in:
Man Utd: Van der Sar, Neville, Ferdinand, Vidic, Evra, Valencia, Fletcher, Giggs, Scholes, Park, Berbatov. Subs: Kuszczak, Carrick, Nani, Rafael da Silva, Macheda, Gibson, De Laet.
Chelsea: Cech, Paulo Ferreira, Alex, Terry, Zhirkov, Joe Cole, Deco, Lampard, Mikel, Malouda, Anelka. Subs: Turnbull, Drogba, Ballack, Kalou, Sturridge, Belletti, Bruma.
12.05: The 'C' word still retains its power to shock, and it was jarring in the extreme to hear 'Crisis' affixed to Chelsea just two weeks ago. Six points and 12 goals later, they're looking a pretty good bet to end the season with their first ever Double, with Manchester United's one-man team rather cruelly deprived of that one man.
So little in this baffling, entertaining and largely low-quality Premier League season has been predictable. But I think we can safely say that this is a Big Game. Victory puts United four points clear with five games remaining, but you can keep an eye of the table here, which updates live throughout the game. Clever.