Manchester United need just four points from three games to claim the Premier League crown after brushing aside Manchester City.
Cristiano Ronaldo and Carlos Tevez, who earlier in the day announced he expects to leave Old Trafford in the summer, were on target before the break to settle a derby encounter in which the hosts were rarely troubled.
Ronaldo opened the scoring in the 18th minute as his free-kick took a wicked deflection off Nigel de Jong in the City wall to wrong-foot goalkeeper Shay Given, who got a hand to the ball but could not keep it out.
And the champions were two goals to the good on the stroke of half-time after Dimitar Berbatov's excellent control and pass found Carlos Tevez, who unleashed a thunderbolt from outside the box which curled home via the inside of the post.
Portugal ace Ronaldo was substituted before the hour mark, much to his disgust, and he spent a good part of the remainder of the match pulling glum faces and shaking his head as he sat on the on the bench.
The Red Devils can now secure the title before Liverpool play again as they travel to Wigan on Wednesday evening before welcoming Arsenal to Old Trafford on Saturday lunchtime, with both games live on Sky Sports 1 and HD1.
Ricky Hatton's presence alongside Rio Ferdinand, who suffered a calf injury in training, ensured there would be plenty of banter in the directors' box as Park Ji-sung dragged his shot wide on United's first attack.
Tevez let fly with a long-range effort that did not really test Given but brought the first 'Argentina' chant from the home supporters.
Elano exchanged passes with Ireland, then fellow countryman Robinho before breaking into the United box, only to miscue his shot, which rolled disappointingly wide.
Ronaldo cut in off the left flank and curled a shot at the City goal which Given got right behind.
A brilliant piece of skill from Robinho took him past Rafael, although Nemanja Vidic was able to get back and clear away from Nedum Onuoha, who had charged up in support.
Elano then cannoned a shot into Ryan Giggs, referee Chris Foy waving away rather hopeful appeals for a penalty.
Richard Dunne came straight through the back of Berbatov to win the ball, although Foy ruled the City skipper had fouled his opponent, much to the frustration of Mark Hughes.
A couple of minutes later, Ireland was the man complaining when Berbatov went down again, with City really having something to moan about from Ronaldo's free-kick.
The distance of around 30 yards was small by the world player of the year's recent standards. And he duly strode up with confidence and fired into the corner, Given wrong-footed by the merest flick off De Jong.
City were having plenty of possession without managing to threaten the home goal. Wayne Bridge curled over a shot from the left flank but Vidic headed clear, then Robinho fired wide after shrugging Rafael off the ball.
Play quickly switched to the other end where a piece of impudence from Patrice Evra offered Tevez the chance to run into space and curl a shot towards the City goal which came crashing back off the angle of post and crossbar.
Bridge nearly got himself into trouble when he lost possession to Park inside his own penalty area, although he recovered quickly enough to make the clearance.
Ireland was cautioned for a late tackle on Evra shortly afterwards before Park won another corner off Bridge when the full-back stuck out a foot to turn the Korean's cross wide.
Yet again, United made nothing of it, although they maintained the pressure, even if Evra flashed a low cross beyond the six-yard box without a team-mate getting anywhere near it.
De Jong tried his luck from 30 yards at the other end but did not trouble Edwin van der Sar.
Then a minute from the break, Fletcher's long ball was neatly controlled by Berbatov. His square pass found Tevez, whose precision shot bounced in off the post.
Fletcher, who will find out on Monday whether he will play in this month's Champions League final, was booked for a foul on Ireland at the start of the second period.
It did not stop United's attacking flow and they came close to grabbing another when Given was nearly caught out by a Rafael cross-shot.
City needed a break and it should have arrived when Elano picked out Robinho with a deft right-wing cross. The £32.5million striker had again got ahead of Rafael and seemed destined to test Van der Sar, only to inexplicably fire well wide.
Micah Richards brought a decent low save out of Van der Sar with an angled drive, then before Felipe Caicedo could get back on the pitch after receiving treatment for a knock sustained on the edge of the box, Paul Scholes and Rooney were introduced for Park and Ronaldo.
Ronaldo did not look too impressed at the decision and was still shaking his head long after he had taken his place in the home dug-out.
Unlike Tevez, only an injury would stop him starting against Barcelona, when he will go head-to-head with Lionel Messi for the world number one crown.
Valeri Bojinov replaced Caicedo shortly afterwards, with Jonny Evans signalling to Ferguson not long after that he needed to come off with what appeared to be a hamstring injury, John O'Shea coming on in his place
Berbatov went close for United before Hughes sent on Martin Petrov in place of De Jong. Giggs let fly with a low volley 10 minutes from time but the effort was always off-target.
The exit of Robinho in the final minute came immediately after Dunne had made a last-ditch tackle to deny Scholes. Fletcher rose to meet the corner, only for Tevez to strike the post with his header as he dived in and made contact less than half a yard out.