Arsenal slipped 14 points off the Premier League pace when they lost 2-0 at Bolton Wanderers on Saturday while champions Chelsea and second-placed Manchester United won.
John Terry headed his first league goal for a year after 62 minutes as Chelsea beat Middlesbrough 1-0 to move to 40 points.
Manchester United ended an emotional week with a win as they easily accounted for Portsmouth 3-0 at Old Trafford on the day of the Belfast funeral of their greatest-ever player, George Best.
United are second on 30 points, Liverpool are third with 28 after beating Wigan Athletic 3-0 while Tottenham Hotspur have 27 after a 3-2 home win over bottom club Sunderland.
Arsenal and Bolton have 26 points, first-half goals by Abdoulaye Faye and Stelios Giannakopoulos having given Wanderers their eighth straight home win in all competitions.
United's game against Portsmouth was preceded by a minute's applause for Best, marking the end of a remarkable week of tributes for the Irish winger, who died eight days ago aged 59.
Manager Alex Ferguson attended Best's funeral earlier on Saturday before flying back for the match.
United won it comfortably with a 20th minute header by Paul Scholes, a shot by Wayne Rooney in the 80th and a delightful close-range chip by Ruud van Nistelrooy five minutes from time.
"The whole ceremony was really touching and emotional, at times it was very difficult," Ferguson said of Best's funeral.
Chelsea rode their luck for the first hour against a lively Middlesbrough before Terry's header from a Damien Duff corner secured the points.
"It wasn't a beautiful game but in the end we deserved the three points and it's one more match gone," Chelsea manager Jose Mourinho told Sky Sports News.
Arsenal have found the Reebok Stadium an inhospitable venue in recent seasons and it was no different on Saturday as they were deservedly beaten.
Faye headed Bolton ahead after 20 minutes and the second goal came 12 minutes later when Gilberto Silva was caught in possession and Giannakopoulos, who secured Bolton's 1-0 win in the corresponding fixture last season, took advantage.
Thierry Henry hit a post two minutes later but Arsenal were below their best and, with less than half the season gone, they can already give up any realistic hope of regaining the title.
"We had a poor first half, Bolton's commitment was high and we gave two easy goals away," said Arsenal manager Arsene Wenger.
Bolton manager Sam Allardyce, whose team have now notched two consecutive league wins against the Londoners after two draws in the past four seasons, said: "We are keeping up an immense record against Arsenal at the Reebok Stadium".
Liverpool's run of six successive wins, all without conceding a goal, has hoisted them into their highest position since December 2002.
Peter Crouch, goalless since his seven million pound ($12.11 million) move from Southampton in July, opened the scoring after 19 minutes though his deflected shot was eventually given as an own goal by flapping keeper Mike Pollitt.
Crouch is claiming the goal but will be less concerned if he loses it having scored the second with a deft finish before midfielder Luis Garcia chested in Livepool's third 20 minutes from time.
Tottenham had to work desperately hard to get past Sunderland, who led with a long-range Dean Whitehead shot after 16 minutes.
Mido and Robbie Keane put Spurs ahead, Anthony Le Tallec equalised on the hour and, after Sunderland keeper Ben Alnwick saved a Keane penalty, Michael Carrick struck the winner 13 minutes from time.
Everton made it four wins in five games with a 2-0 success at Blackburn Rovers, who had Andy Todd sent off after half an hour.
Everton won with first half goals by James McFadden and Mikel Arteta -- the first time in 19 games this season they have scored more than once.
Newcastle United drew 1-1 at home to Aston Villa after Gareth Barry missed a late penalty for the visitors, and West Brom drew 0-0 with Fulham at the Hawthorns after the Londoners had Luis Boa Morte sent off at the end of the first half.