United executed the perfect contain-and-counter performance to notch a fifth win in six years at Liverpool, with Carlos Tevez scoring the only goal at Anfield.
The Argentine striker clipped home Wayne Rooney's shot after 43 minutes, while the stars of the show were undoubtedly United's backline and defensive midfielders.
Liverpool forged no clear-cut opportunities of their own, although two quickfire rare lapses from Edwin van der Sar in the first half twice saw United defenders forced into clearing the ball from their own goal line.
United's first half display was all about sitting back and inviting Liverpool onto them. As hosts, and with a six point deficit to make up, the pressure was on Rafa Benitez's side to make the early running.
Aside from a couple of early efforts from Sami Hyypia, there was little to concern United. Liverpool did force a couple of openings, but largely through uncharacteristic lapses from van der Sar.
The veteran Dutchman twice collided with his own defenders and failed to make contact with the ball, and each misjudgement ended with the ball being cleared off the line.
First Anderson had to parry away Kewell's shot - from which Fernando Torres headed the rebound woefully wide - then two minutes later Patrice Evra slid in to clear the ball to safety as it rolled goalwards off the back of Rio Ferdinand.
The England international defender was visibly irate at his goalkeeper's misjudgements, mindful of the need for calm heads in the Anfield cauldron.
That brief slip aside, such a clinical attitude was the story of much of United's display. And, having soaked up the hosts' pressure for much of the half, they struck two minutes before the interval. Just as last season, it was a set-piece which did the damage.
The Reds committed several players into the area, all of whom were duly marked. Rooney remained outside the box, allowing him room to run onto Giggs' clever corner and drill a shot goalwards. Although the low effort was heading wide, Tevez was on hand to divert the ball into the roof of the Kop net.
Just as they did at the Emirates Stadium against Arsenal last month, United had taken the lead at the perfect time. The key was to remain firm and in control for the entire second half.
Aside from an early effort from Torres, the Reds managed to keep their hosts at arm's length throughout. While it made for nervy watching, the gameplan of absorbing pressure and duly counter-attacking, Sir Alex Ferguson's side largely executed it to perfection.
Van der Sar had no meaningful shots to save, comfortably fielding long-distance efforts from John Arne Riise and Dirk Kuyt. The big Dutchman was well beaten, however, by compatriot Ryan Babel, who arrowed a 20-yard effort just wide of the post with 15 minutes remaining.
Liverpool's inability to break down the United defence saw them resort to pumping deep crosses into the area, with van der Sar, Ferdinand or Vidic always equal to their efforts.
The hosts' need to bombard forward saw gaps begin to open up, and Rooney could easily have doubled the Reds' lead with 12 minutes remaining, but he could only divert the ball wide from Ronaldo's left-wing cross.
While he may well have done better, Rooney continued to give an outstanding display of hold-up play as United ran down the clock. The game's dying embers passed without major incident, allowing Sir Alex to savour a relatively comfortable victory in his 50th match against Liverpool.
Crucially too, in this season's title race, the result saw United move nine points clear of their hosts. From three games against their predicted titles rivals so far this season, only an injury time equaliser from Arsenal's William Gallas have prevented United taking nine points.
Liverpool: Reina; Arbeloa, Hyypia, Carragher, Riise (Aurelio, 80); Benayoun, Gerrard, Mascherano, Kewell (Babel, 66); Kuyt (Crouch, 73), Torres.
Subs not used: Itandje, Lucas.
Bookings: Gerrard, Mascherano.
Manchester United: Van der Sar; Brown, Ferdinand, Vidic, Evra; Ronaldo, Hargreaves, Anderson (O'Shea, 90), Giggs; Rooney, Tevez (Carrick, 83).
Subs not used: Kuszczak, Fletcher, Saha.
Bookings: Evra, Anderson, Brown.