Chelsea ensured they will be top of the Premier League on Christmas Day after a hard-fought victory over Stoke City at the Britannia Stadium.
John Terry's header inside two minutes kick-started a spiky contest that threatened to spill over at times.
Yet for all Stoke's desire, Chelsea always looked in control and deservedly doubled their lead through Cesc Fabregas's scuffed finish.
Steven Nzonzi had Stoke's best chance but his deflected shot was well saved.
Victory took Chelsea three points clear of second-placed Manchester City.
The only blight on Chelsea's night came with a late injury to Eden Hazard, who limped off after appearing to injure an ankle in a tangle with Jonathan Walters.
Ahead of the kick-off, much talk centred on the hackneyed issue of whether Chelsea's stars could perform on a cold December night in Stoke.
Those inside the Britannia Stadium did not have to wait long for an answer, with barely 90 seconds on the clock when the visitors went in front.
After Branislav Ivanovic's shot from Chelsea's first attack was charged down, Terry's unchallenged header from Fabregas' resulting corner powered past the exposed Asmir Begovic.
Tempers nearly boiled over when Phil Bardsley went in hard on Hazard as the Belgian advanced down the left.
The tackle enraged Chelsea manager Jose Mourinho but referee Neil Swarbrick showed only a yellow card.
Stoke perked up and almost levelled when Nzonzi's low strike deflected off Terry and forced a wonderful save down low from Thibaut Courtois, recalled in place of Petr Cech after a muscular injury.
Diego Costa should have doubled Chelsea's lead after half-an-hour when he raced clear on to Fabregas' through ball but dragged his low drive just wide.