(CNN) -- The Premier League title race was thrown wide open on Saturday as Liverpool crushed 10-man Manchester United 4-1 at Old Trafford to move to within four points of the defending champions.
Liverpool celebrate Fabio Aurelio's superb free-kick as they crushed Manchester United 4-1 at Old Trafford.
Rafael Benitez's side superbly responded from going a goal behind as Fernando Torres and Steven Gerrard turned the match on its head before the break, with Fabio Aurelio and Andrea Dossena easing Liverpool well clear in the second half.
In contrast, it was a day to forget for United defender Nemanja Vidic, who gifted Torres the equalizer before being sent off against Liverpool for the second time this season.
Both teams went into the match after superb midweek Champions League victories over Inter Milan and Real Madrid, but Liverpool began the strongest and were unfortunate to go behind against the run of play.
Argentine striker Carlos Tevez played a superb through ball for Park Ji-sung who was clipped by on-rushing goalkeeper Pepe Reina. Cristiano Ronaldo duly put away the 23rd minute penalty, his 17th goal of the season, to put United ahead.
But, five minutes later, Liverpool were level thanks to a rare mistake from Vidic.
The Serb let Martin Skrtel's long punt forward bounce when he could have easily headed it back into the Liverpool half. Then, he failed to deal with the loose ball, allowing man-of-the-match Torres to nip in and streak clear, beating goalkeeper Edwin van der Sar with clinical efficiency.
Then, on the stroke of half-time, Liverpool scored again. Hull were the last team to score more than once against United in the Premier League -- and that was four-and-a-half months ago.
However, that changed when Torres sent Gerrard racing into the box only for French full-back Patrice Evra to mis-time his tackle in the penalty area. Gerrard picked himself up to convert the resulting penalty and put Liverpool ahead.
United manager Sir Alex Ferguson made a triple substitution in the second half, bringing on Dimitar Berbatov, Ryan Giggs and Paul Scholes, but any hope the substitutes had of changing the game evaporated within a minute of their introduction.
Another woeful mistake from Vidic left the Serbian little alternative other than to haul down Gerrard, bringing him his second successive red card against Liverpool.
And, as Vidic was walking down the tunnel, Aurelio superbly curled home the resulting free-kick to make the points safe and consign United to their first home defeat of the season.
To rub salt into United's wounds, Dossena lobbed Van der Sar in the final minute as Liverpool completed their biggest win at Old Trafford since 1936.
Liverpool's victory means they have completed a 'double' against both United and Chelsea this season, reviving their flagging title hopes in the process.