Liverpool routed Premier League leader Manchester United 4-1 on Saturday to revive its faltering title chase.
Captain Steven Gerrard gave Liverpool the lead for good just before halftime after Fernando Torres tied it following Cristiano Ronaldo's penalty kick for United.
The Reds secured their first win at Old Trafford in five years, leaving the defending champions humiliated by their fiercest rival. Any doubt about the outcome was removed in the last 15 minutes with goals by Fabio Aurelio and Andrea Dossena.
United's miserable afternoon was compounded when defender Nemanja Vidic was ejected for the second time this season against Liverpool.
"It's a hard one to take, particularly because I thought we were the better team," said United manager Sir Alex Ferguson, whose team is chasing five titles this season and has already won the Club World Cup and the domestic League Cup. "We have to accept it was a bad day in terms of the goals we lost, but I couldn't fault the display that much."
Gerrard said he hoped the result might encourage other teams to put pressure on United even at Old Trafford.
"The important thing is that we have made the gap smaller. We realize that Manchester United are a fantastic team and there's still a lot of work to do," the Liverpool captain said.
"We'll need a little bit of luck along the way but hopefully that gives teams that are going to play against Manchester United a bit of belief that they can be beaten. And hopefully it will give us a lot of confidence to go on and win as many games as we can."
United is still four points ahead of Liverpool with a game in hand.
The result also gave Chelsea renewed hope of winning the title.
The Blues, who are seven points behind United, host Manchester City on Sunday. United has 65 points from 28 games, Liverpool 61 from 29 and Chelsea 58 from 28.
With Aston Villa not in action until Sunday's game at home to Tottenham, Arsenal moved up to fourth place and the last Champions League spot by beating Blackburn.
Andriy Arshavin's first goals for Arsenal helped the Gunners up to fourth place in a 4-0 victory. Signed during the January transfer window from Zenit St. Petersburt, Arshavin scored in the second and 65th minutes.
Emmanuel Eboue added the other two in the last three minutes, the fourth coming from the penalty spot. Arsenal has 52 points from 29 games, leading Villa on goal difference having played one more game.
Everton is sixth with 48 from 29 after beating struggling Stoke 3-1.
Brazilian star Jo and defender Joleon Lescott put Everton 2-0 up inside the first 24 minutes and, although Ryan Shawcross replied for Stoke in the 52nd at Goodison Park, Marouane Fellaini added a third for the Toffees in the final minute.
The loss leaves Stoke in the relegation zone with two points more than next-to-last Middlesbrough, which needed a last-minute equalizer by Marlon King to salvage a point in a 1-1 draw at home to Portsmouth. Peter Crouch scored for the visitors in the 30th minute.
Michael Owen returned for Newcastle in a 1-1 draw at Hull after missing five games with an ankle injury. Geovanni put Hull in front in the ninth minute but Steven Taylor's 38th-minute volley captured a valuable point for the Magpies.
Wigan won 2-1 at Sunderland with goals by Ben Watson and Charles N'Zogbia and Fulham triumphed 3-1 at Bolton with strikes by Andy Johnson, Simon Davies and Diomansy Kamara.