Premier League leaders Manchester United beat Charlton Athletic 2-0 at Old Trafford to stay six points clear of Chelsea on Saturday after the champions beat Middlesbrough 3-0 at Stamford Bridge.
South Korea midfielder Park Ji-sung and Scotland's Darren Fletcher scored in each half to take Alex Ferguson's side to 66 points and a step closer to their first league title since 2003.
Ivory Coast striker Didier Drogba scored twice for Chelsea from freekicks and Boro defender Abel Xavier gifted them the other by deflecting an Arjen Robben effort into his own net.
Liverpool lost 2-1 at Newcastle United, Reading were 2-0 winners over Aston Villa, Sheffield United beat Tottenham Hotspur 2-1 and Watford won a relegation scrap at West Ham United 1-0 after Marlon Harewood missed a penalty for the hosts.
Striker Andy Johnson celebrated his 26th birthday by scoring Everton's winner as they beat Blackburn Rovers 1-0.
Though Manchester United's victory did not increase their lead, Ferguson's men will at least be comforted by knowing there are now only 11 games left in the season.
Park delivered the killer blow with a header from French wingback Patrice Evra's cross in the 24th minute and Fletcher wrapped up the win with another header off a Wayne Rooney cross in the 82nd.
"Credit to Charlton...they made it difficult for us," Ferguson told Sky Sports News.
"There wasn't any great goal threat from them but when you're only 1-0 in front it only takes a second to lose a goal and that was worrying for me and probably for everyone watching."
Chelsea lacked fluency against a Boro side who had beaten them 2-1 at the Riverside in August but made the breakthrough with Drogba's freekick on the stroke of halftime.
Xavier put the result beyond doubt by turning in a wayward shot by Dutch substitute Robben, who had only arrived a minute earlier, and Drogba finished the job to become the Premier League's leading scorer with his 17th of the season.
Along with the points, Chelsea also made sure of a three-year run without a home league defeat -- the last coming against Arsenal in a London derby on Feb 21, 2004.
Their next home fixture is next month against Sheffield United.
Asked about the title race, Chelsea's assistant manager Steve Clarke told Sky Sports: "We're enjoying the chase, and I think you can see that.
We're winning the matches we have to win, we know we have to keep winning and the more we win the more pressure we try to put on Manchester United.
"They're having a great season, but if they make any mistakes -- we'll be there."
With 60 points, Chelsea now have a useful lead over Liverpool, who are stuck on 50 after letting slip an early lead at St James' Park from their former Newcastle forward Craig Bellamy, who was booed on his return.
Nigerian striker Obafemi Martins equalised after a goalkeeping blunder by Liverpool's Jose Reina and Peruvian midfielder Nolberto Solano converted a penalty to win it.
Liverpool manager Rafael Benitez told their Web site (www.liverpoolfc.tv): "In the first half we should have been three or four nil up but we then conceded a stupid goal and a stupid penalty.
"It's difficult to explain how we got nothing from this match."
Fourth-placed Arsenal, who play Wigan Athletic on Sunday and have a further game in hand, have 46 points.
Down at the other end of the table, Watford remain bottom after Darius Henderson secured their first away league win of the season with a 12th minute penalty.
But it did move them on to 18 points -- just two behind Charlton and West Ham and seven adrift of Wigan.
There was an eventful evening match at Portsmouth where the home side beat Manchester City 2-1 to end a six-match league run without a victory.
Portuguese midfielder Pedro Mendes, knocked unconscious when Portsmouth played City in August, again left the field on a stretcher after Joey Barton clipped his Achilles heel to earn a yellow card.
Portsmouth manager Harry Redknapp was ordered out of the dugout for protesting about the foul.
Mendes had given Pompey the lead with a superb strike after five minutes. Bernardo Corradi equalised for City before substitute Nwankwo Kanu grabbed the winner nine minutes from time.