Eden Hazard starred for Chelsea as he scored one and set up another in a hard-fought 2-1 Premier League victory over Brighton and Hove Albion.
Hazard netted a double in Chelsea's 4-0 win in the corresponding fixture last season, and the winger dazzled Brighton in the first half on Sunday.
With Pedro having benefited from Hazard's exceptional play for Chelsea's opener, the Belgian doubled the visitors' advantage with his first goal in eight games just after the half-hour, although he was replaced late on after picking up a knock.
Solly March's close-range finish after Marcos Alonso had hit the woodwork set up a grandstand finish, but Chelsea held firm to move back within two points of third-placed Tottenham.
Buoyed by his goal against Manchester City, David Luiz had Chelsea's first attempt, Mat Ryan doing well to judge the defender's dipping free-kick.
But Ryan was beaten in the 17th minute, as Hazard came to the fore.
After seeing his initial shot blocked, Hazard capitalised on the ricochet, driving into the area before sliding a disguised pass to the far post, setting up Pedro for a simple finish.
Hazard turned from provider to scorer 16 minutes later, racing clear of Brighton's defence to latch on to Willian's throughball and slot beyond Ryan.
Chelsea should have been out of sight early in the second half, but Hazard failed to tuck in Cesar Azpilicueta's pinpoint cross before Alonso's venomous effort clattered off the upright.
Brighton made their good fortune count when March tucked home in the 66th minute, though it was ultimately the sensational first-half display from Hazard – who left the field seven minutes from time following a heavy challenge from Dale Stephens – that proved decisive, with Lewis Dunk heading wide from six yards out in stoppage time.
What does it mean? Chelsea tighten their grip on fourth
The Blues are now on 37 points, two behind Tottenham but, perhaps more importantly, three ahead of Arsenal, whose unbeaten run came to an end with a 3-2 defeat at Southampton. Brighton, meanwhile, remain 13th, but with a five-point cushion between themselves and Newcastle United a place below.
Electric Hazard runs riot
After his crucial part in Pedro's opener, Hazard claimed an assist for the fourth consecutive Premier League match – a career first, and the first time a Chelsea player has done so since Cesc Fabregas in September 2014. Not content with that, Hazard got in on the action with a typically composed finish, ending a run of seven league games without a goal.
17 - Eden Hazard has been directly involved in more Premier League goals this season (17 in 16 apps) than he was in the whole of last season (16 in 34 apps). Evolved. pic.twitter.com/RsYVl9zuuR— OptaJoe (@OptaJoe) December 16, 2018
However, an apparent ankle knock picked up in the second half will be of concern to Chelsea boss Maurizio Sarri.
Sloppy Brighton only have themselves to blame
Chris Hughton was rightly furious after Hazard slipped in Chelsea's second. While the first goal was down to individual brilliance, the second – which in the end proved crucial – was due to slack play from the hosts, with Leon Balogun's wayward pass enabling Willian to pounce, and Hazard did the rest.
Bournemouth are the next opposition for both Brighton and Chelsea. Eddie Howe's side travel to Stamford Bridge in the EFL Cup on Wednesday, before facing the Seagulls in the league on Saturday.