Chelsea secured their 11th straight Premier League win at Selhurst Park after Diego Costa scored the only goal to hand the Blues a 1-0 win against Crystal Palace.
The Chelsea striker headed in the winner in the 43rd minute, which had been set up by Cesar Azpilicueta, to send Antonio Conte’s men nine points clear of second-placed Arsenal, who can reduce that gap on Sunday.
While Chelsea managed to match their 11-game winning streak from 2009, Palace’s second successive top-flight defeat leaves Alan Pardew’s side rooted in 16th place.
Despite Palace coming into the London derby hovering in the precarious position just above the relegation zone, though, it was the Eagles who started off the clash the better team – with the home side dominating much of the play in the early stages.
Neither Palace nor Chelsea could create a clear-cut chance in the opening 10 minutes of the match, however, although the league leaders were first to be given the opportunity to score when Joel Ward pulled back the returning Eden Hazard.
David Luiz sent his low effort into the Palace wall and out for a corner, which Chelsea could not subsequently make anything off. The Blues, though, slowly began to find their rhythm but it was Palace who twice had the best opportunity to take the lead.
Jason Puncheon, who returned to Pardew’s starting line-up having missed the defeat to Manchester United through suspension, was at the heart of both chances with the forward first sending Martin Kelly’s square-ball from the right wide before his 39th-minute free kick hurtled over the crossbar.
Conte was handed some disappointing news when Costa received his fifth booking of the season for his foul on Joe Ledley, which will rule the striker out of Chelsea’s Boxing Day game at home to Bournemouth
But it didn’t dishearten the Brazilian, who subsequently headed the Blues in front minutes before the break with his superb header from Cesar Azpilicueta’s cross.
The move for the goal was started by Hazard, who delivered a cross to Azpilicueta which allowed the full-back to race forward and set up Costa.
The 28-year-old got the better of Palace defender Scott Dann to hand the Blues the lead and score his 13th goal of the season – his 50th in all competitions since arriving in England two years ago.
Despite the blow, Palace returned from the break and immediately went about testing Thibaut Courtois. Gary Cahill failed to clear a long ball over the top, which allowed Yohan Cabaye to win it and then drive a low shot towards goal – which Courtois dived to save.
The Eagles followed the shot up with a sustained period of possession and pressure but, they couldn’t find the all-important equaliser as Chelsea continued to test Wayne Hennessey.
N’Golo Kante sent a powerful, long-range effort hurtling towards the goal, which the Palace goalkeeper managed to parry clear before the introduction of Cesc Fabregas – who scored the winner against Sunderland – for Willian added more speark to the visitors’ attacking play.
Kante then saw a low effort once again saved by Hennessey, but the midfielder was handed a blow when he was shown his fifth yellow card of the season, which will also ruled him out of the Bournemouth game alongside
Hennessey was needed soon after to deny Marcos Alonso’s powerful effort before the Palace goalkeeper would have breathing a sigh of relief when the Chelsea full-back’s free kick smashed off the crossbar.
The visitors remained in control in the final stages of the game, and held out to secure their 11th consecutive victory in the Premier League to consolidate their position at the top of the table.