Good evening and welcome to Sports Mole's live text coverage of arguably the biggest Manchester derby in living memory.
Tonight's encounter at the Etihad is seen by many as a title-decider as a win for visitors United would see them move six points clear atop the Premier League, while victory for City would see Roberto Mancini's men move above their rivals on goal difference with just two games of the season remaining.
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FULL-TIME: That's it! City win and go top of the table on goal difference!
It's a huge result for the blue half of Manchester who go above their great rivals thanks to Kompany's free header in added-on time in the first half. Ferguson and Mancini shake hands, which is nice to see after their earlier scuffle. City's goal-difference advantage is eight, a deficit that could be turned around with two games to go. You'd have to make City favourites though. Thanks for joining Sports Mole this evening, good night!
90+5 min: Late corner for United. Last chance saloon if ever I've seen it.
90+3 min: Mancini makes his final change as Milner replaces Nasri. Two minutes left.
90+2 min: Yaya earns a free kick and City will waste more precious seconds.
90 min: Nasri should make it two but he delays shooting too long and the ball is cleared. Five minutes added on.
88 min: De Gea beats away a bullet Clichy effort as City almost seal the win.
87 min: Aguero earns a free kick in the corner but it's cleared and Young looks to counter but his pass is wasteful. Time running out for the Red Devils.
82 min: Oh so close to a City second as Yaya rushes clear. The Ivorian should perhaps feed Aguero but he goes alone and curls a left-foot effort inches wide of the post. Ashley Young enters the fray for Nani as Micah Richards takes the place of Silva.
81 min: Ten minutes for United. It's not been in keeping with some of this season's goaltastic encounters but it's been absorbing all the same. I want to see Balotelli on for the final ten!
78 min: Aguero wins the ball down the right and works a couple of yards but the angle's tight and he can only find the side-netting. Valencia replaces Scholes as Carrick is also booked for another late tackle on Barry.
76 min: Welbeck rolls around Spanish-style after a bad tackle from behind by De Jong who gets himself in the book already. On the touchline Fergie and Mancini confront each other. The elder statesman's getting riled I think. In for a cracking final 15 I reckon.
72 min: Yaya breaks away and decides not to find Aguero and go for goal himself, fizzing a shot wide of De Gea's near post.
69 min: Jones goes into Marriner's book for a lunge on Barry. Around 20 minutes left for United to salvage something. Surely we'll see Valencia, Young or Hernandez soon?
68 min: The Dutchman comes on in place of Carlos Tevez, who's had a quiet night at the office.
66 min: De Jong's getting stripped off to come on for City as Mancini looks to defend the narrow one-goal lead.
64 min: Jones delivers a dangerous ball that Lescott cuts out at the near post. Set piece opportunity for the visitors that lands at Rooney's feet at the back post. His cross is floated into a dangerous area but there's no one attacking it which makes Rooney furious with his teammates.
62 min: Almost two for City as Yaya makes space under the attentions of Rooney and drills in a low cross that De Gea clears with his foot.
57 min: Aguero feeds the onrushing Zabaleta but Smalling gets across to clear the danger. United make their first change as Park is replaced by Welbeck. Rooney should get more support up top now.
53 min: Yaya gets a stupid booking for thrashing the ball into the turf after clearly obstructing Giggs. United still yet to have a real goalscoring opportunity in this match. Pictures show Valencia, Hernandez and Young just sitting on the bench, not warming up. Yet.
50 min: Ferdinand pings a quality ball to Nani, who smashes a left-foot effort towards Hart's near post. The England stopper again looks unsure, fumbling the ball out for a corner.
48 min: United win an early corner, which Giggs swings over with Hart uneasy in flicking it away from the awaiting Rooney.
46 min: Second half underway. Can United find a goal? A draw will certainly suffice from here for the visitors. No changes from either side.
HALF-TIME: City 1-0 United
What a moment for City's leader to put the Blues ahead right at the end of the opening 45. United's marking looked suspect to say the least. City had the better of the play and probably deserve to be ahead going into the dressing room. Will Fergie make a half-time change and bring on one of his more attacking players? Stick with us on Sports Mole to find out.
45 min: GOAL! Kompany puts City ahead!
Big, big goal in the Premier League title race as the City captain rises highest to head home a Silva corner after a prolonged period of pressure from the home side.
41 min: Looks like a cracking end to the half as Nani's deep cross is volleyed back across goal by Rooney with Zabaleta clearing the danger. Both sides looking for a breakthrough to make the upcoming 15-minute break that bit easier.
40 min: Rooney starts a United move but it breaks down and Tevez sprints away on the counter. The Argentinian finds Yaya but the chance is eventually blown as Aguero dilly-dallies for too long.
39 min: Patient build-up from City ends up with a dangerous centre from Clichy being claimed by De Gea. United need to stem the flow.
36 min: City really bossing proceedings right now as Zabaleta charges into the area but gives De Gea an easy save to make.
35 min: Marriner's keeping a cool head in charge of this game at the moment. I'll be amazed if he's still so calm by the end with an impatient crowd and players. City taking up the ascendency as Aguero screws wide.
33 min: Players from both sides getting increasingly frustrated as the game gets ever bittier.
31 min: Rooney looks a bit riled and I think Kompany's enjoying it. The Belgian needs to be careful, however, as he's on a booking.
29 min: Evra allows his France teammate Nasri to skip past far too easily but the former Arsenal man's cross doesn't beat the first man.
25 min: Rooney hoofs the resulting delivery high into the Manchester sky and the ball is flicked to Aguero but his volley is sliced high, wide and handsome.
24 min: Clichy bursts forward from left-back and finds Aguero but he's crowded out in the area and can only win a corner.
21 min: Pictures show Argentina legend Diego Maradona watching on in the crowd - he's Aguero's father-in-law, you know. Great footballing family.
20 min: City captain Kompany receives a very harsh booking for a slightly late challenge on Rooney, who in all honesty followed through into Kompany's tackle.
19 min: Both teams definitely feeling each other out early on. Although that's not too surprising as neither club have conceded a goal in the opening 15 minutes of a Premier League game in 2011-12.
16 min: First big chance as Nasri dances round the United defence before feeding Tevez. The Argentine fizzes across the area but it's well cleared by Jones with Aguero waiting behind to tap home.
14 min: No real goalscoring chance of note so far although it's still engrossing viewing. Absolutely nothing from Tevez and Aguero while Rooney is looking mean in United's attack.
11 min: To use an old football cliche, it's a real cauldron inside the Etihad at the moment. The home fans giving off a real hostile, Nou Camp-like atmosphere. Doesn't seem to be intimidating United's experienced men.
10 min: City have been a little wasteful in possession and Nani is given a long-range shooting opportunity but he blazes into row Z.
9 min: Weak United appeal for handball as Smalling heads at Kompany, replays show it hit the Belgian square in the chest.
6 min: Silva has a couple of shots from outside the box with the first blocked before winning a corner with the second. The Spaniard takes it but it comes to nothing.
5 min: City go close to the United box for the first time but Clichy's cross is too long for Tevez. Up the other end Nani is played through but his first touch is disappointing and allows Lescott to clear.
4 min: Looks like Smalling's starting at centre-back, not Jones, who can be excellent roaming forward.
2 min: Early corner for United and there's danger as Nani floats over a cross that is headed high above Hart. The England keeper manages to punch partially clear to Carrick, whose shot hit Kompany and was finally cleared. Strong start for the Reds.
1 min: We're underway as Andre Marriner blows his whistle for the first time. Here's to an engrossing 90 minutes of Mancunian football.
19.55: Evra and Kompany stand straight-faced side-by-side in the tunnel. Emergence onto the pitch imminent. Is it me or do those players look nervous?
19.50: Read in full what Sir Alex said here. Around 10 minutes from kickoff now, personal prediction from me is 2-2. Gonna go all out and say Nasri for the first goalscorer.
19.42: For more on what Mancini said click here. Fergie just getting interviewed now, confirming that experience was a key part of his selection plans. He clearly wants to control the game in midfield but reiterates that he has "never in my life" played for a draw.
19.32: Mancini's just had his pre-match interview and he says he's not that surprised by Fergie's changes. He also expresses his confidence that his side can get the win they need to go top of the table. The Italian thinks that United might be going for a draw as that will be enough for them to keep a three-point lead.
19.22: From the bench City have Richards, Kolarov, De Jong, Milner, Balotelli & Dzeko to call upon while the Red Devils have just one defender on the bench in Rafael. Fergie has the likes of Valencia, Young, Welbeck, Berbatov and Hernandez to bolster his attacking options.
19.15: So Mancini's named a much more attacking lineup with Yaya, Silva, Nasri, Tevez and Aguero all starting. Fergie's named a much more experienced, solid team with Carrick, Scholes, Giggs and perhaps most surprisingly Park getting the nod. Will Rooney be able to get the better of the impressive Kompany and Lescott? So many questions!
19.07: Here's the United XI. Plenty of changes from Fergie, unlike his Italian counterpart. Smalling comes in at right-back with Jones replacing Evans alongside Ferdinand in the heart of defence. Fergie's favourite big game player Park is chosen ahead of both Valencia and Young while Rooney starts on his own up top. Full United lineup: De Gea; Smalling, Jones, Ferdinand, Evra; Nani, Carrick, Scholes, Giggs, Park; Rooney
19.04: City team news is in. Tevez and Aguero lead the line, despite the availability of the returning Balotelli. Zabaleta keeps his place at right back ahead of Richards in an attacking XI. Here's the full Blues lineup: Hart; Zabaleta, Kompany, Lescott, Clichy; Barry, Y Toure, Silva, Nasri; Tevez, Aguero
19.01: Hello all, I'm really hoping for a barnstorming encounter tonight. I can't think of many bigger Premier League games in recent years, especially with the local element included.
