Chelsea tightened their grip on the Premier League title race on Saturday after they won 2-1 at Liverpool and Manchester City dropped points at second-bottom Queens Park Rangers.
After Diego Costa's 10th goal of the campaign had given Chelsea victory at Anfield, Southampton kept pace with a 2-0 win over Leicester City, but City are now eight points off top spot after drawing 2-2 at QPR.
Bidding to avenge their costly 2-0 loss in last season's corresponding fixture, scene of captain Steven Gerrard's infamous slip, Liverpool took a ninth-minute lead against Chelsea through Emre Can's deflected shot.
But Gary Cahill forced the ball past Simon Mignolet to equalise almost immediately before Costa slammed home 23 minutes from time to safeguard Chelsea's four-point advantage at the summit.
"It was a fantastic performance. The players as individuals all had a great performance and as a team they were in control," Chelsea manager Jose Mourinho told BT Sport.
"One point at Anfield, most teams would accept that as a great result. This team did not accept that and I am really, really pleased."
Runners-up to City last season, Liverpool have now lost three successive games in all competitions and trail Chelsea by a huge 15 points.
Liverpool manager Brendan Rodgers felt that his side should been awarded a late penalty after a shot from Gerrard struck Cahill on the arm in front of the Kop.
"We worked so hard in the game, but we need those decisions that are obvious," he said.
"It was a clear, clear penalty. I was very disappointed because the players gave everything in the game."
Chelsea were on course to move six points clear until substitute Shane Long scored a quick-fire late brace to earn second-place Southampton victory over Leicester at a soggy St Mary's.
Long curled home from Graziano Pelle's lay-off in the 75th minute before running clear and beating Kasper Schmeichel five minutes later to keep Ronald Koeman's side on Chelsea's tail.
Mata revives United
But City were unable to follow suit at a rain-lashed Loftus Road and having suffered a costly loss at home to CSKA Moscow in the Champions League on Wednesday, they have picked up only one win in their last six games.
QPR striker Charlie Austin saw two goals disallowed as the hosts made a determined start - one for offside, the other after City goalkeeper Joe Hart inadvertently kicked the ball twice as he took a free-kick.
Austin's perseverance paid off in the 21st minute when he fired home from Eduardo Vargas's pass, only for Sergio Aguero to equalise 11 minutes later after coolly plucking Eliaquim Mangala's pass out of the sky.
After City had lost substitute Edin Dzeko to injury just four minutes after he came on, they saw Martin Demichelis head Austin's cross into his own net to restore QPR's lead in the 76th minute.
But seven minutes from time, Aguero scampered onto a pass from Yaya Toure before rounding Rob Green and drilling into the net to limit the damage for City.
"It was a very difficult week. We didn't have 72 hours to recover physically and mentally from the last game but we tried until the last minute to win," Pellegrini said.
"We are in an unlucky moment. We are not playing very well but we had enough chances to win this game.
"I am not worried about Chelsea. We will see if they can continue that until the end of the year."
Elsewhere, Manchester United had substitute Juan Mata to thank after they secured a 1-0 win at home to Crystal Palace that lifted Louis van Gaal's side up to sixth place, 13 points below Chelsea.
United toiled in the first half and saw former player Fraizer Campbell spurn a chance to put Palace ahead when he lobbed over following a mix-up between auxiliary centre-back Daley Blind and 19-year-old Paddy McNair.
But Mata scored just four minutes after coming on in the 63rd minute to give United victory, deceiving visiting goalkeeper Julian Speroni with a deflected 22-yard shot after a one-two with Angel di Maria.
"It was a fantastic goal, but it was important also," said United manager Louis van Gaal.
"I am pleased because we have three points and there is an international break so it was important we closed with a victory."
West Ham United inched above Arsenal into fourth place despite drawing 0-0 at home to Aston Villa, while Ashley Barnes's solitary header earned bottom club Burnley a first win of the campaign at home to Hull City.