Premier League leaders Manchester United piled the pressure on second-placed Liverpool by moving six points clear at the top with a 2-0 win away to relegation-threatened Middlesbrough on Saturday.
Goals either side of half-time from Ryan Giggs and Park Ji-Sung ensured an easy win for Sir Alex Ferguson's reigning champions at the Riverside Stadium.
Liverpool will narrow the gap to three points again if they beat another relegation candidate in Newcastle on Sunday but, whatever the result at Anfield, they will still have played one game more than United.
Defeat left Middlesbrough second bottom in the table and still three points short of safety.
"It was a very good performance in the sense that they all worked their socks off," said Ferguson, whose side are bidding to equal Liverpool's record of 18 English titles.
Chelsea, at full strength ahead of the second leg of their Champions League semi-final second leg against Barcelona, moved level on points with Liverpool after a 3-1 home win in the west London derby against Fulham, the first three goals coming in the opening 10 minutes.
The match at Stamford Bridge was not yet 60 seconds old when Nicolas Anelka scored after Florent Malouda's cross was held up by Didier Drogba.
But Chelsea's lead lasted just three minutes before Erik Nevland unleashed a shot which Petr Cech got a hand to but could not keep out.
Fulham, the surprise package of the Premier League season, were behind again in the 10th minute when John Pantsil was unable to cut out Drogba's cross and Malouda scored at the back post.
Drogba got on the scoresheet early in the second-half after strike partner Anelka returned the Ivorian's earlier favour.
Elsewhere Arsenal's 3-0 win away to Portsmouth at Fratton Park ensured the 'Big Four' - United, Liverpool, Chelsea and the Gunners - would all look down on the rest of the table come the end of the season.
Victory left fourth-placed Arsenal 13 points clear of Aston Villa with only a maximum of 12 available to the Midlands club, who play Hull on Monday
