Two second-half goals from Wayne Rooney secured victory over rivals Liverpool and propelled Manchester United back to the top of the Premier League table.
The 26-year-old striker netted a quick brace within five minutes of the restart, first firing in from close-range following a Ryan Giggs corner.
Rooney then doubled United's lead three minutes later when he was played through one-on-one, keeping his cool to slot past the helpless Pepe Reina in goal for the visitors.
Luis Suarez grabbed a consolation for Kenny Dalglish's Reds with ten minutes left on the clock, but that wasn't the only flashpoint the Uruguayan was involved with, after controversially refusing to shake Patrice Evra's hand in the build up to the game.
As a result of the South American's action, fellow United defender Rio Ferdinand then withdrew his own hand to Suarez.
Suarez was in the thick of the action from the off, supplying a neat ball to Glen Johnson just inside the 10-minute mark. The full-back cut in from the right before sending a curling left-foot shot just wide of David de Gea's right-hand post.
However, clear-cut opportunities were rare in a quiet first half, with Paul Scholes guilty of missing United's best chance when he headed straight at Reina from six yards out.
Following his quickfire double, Rooney could have had a hat-trick after Antonio Valencia and Scholes combined to put the England international through once more, but the striker - starting his 500th career game for the Red Devils - prodded just wide.
The win keeps pressure on Manchester City at the top of the table, while Liverpool's loss mean they run the risk of falling seven points behind the Champions League qualification places.