Just three places may have separated the two teams at the start of play, but Chelsea and West Ham were leagues apart on Boxing Day. For a couple of hours at least, Chelsea extended their lead atop the Premier League table to six points, courtesy of a performance at Stamford Bridge that simply oozed the class and force of champions. John Terry diverted in a first-half corner before Diego Costa struck clinically after the interval to give Chelsea a 2-0 victory in a match they dominated from start to finish.

On the three previous occasions that Chelsea have topped the Premier League on Christmas Day, they have gone on to claim the title. And, Despite Manchester City’s impressive form to keep the race very much alive, it would take a large helping of bravery to bet against them continuing that record this season. Despite the busy run of fixtures ahead, as he has throughout the season, Jose Mourinho maintained a consistent lineup for this Boxing Day clash. His counterpart decide otherwise, with Sam Allardyce leaving two of his star men this season, Alex Song and Diafra Sakho, on the bench.

There was a change of formation, too, from the midfield diamond and two-man strike force that has lifted West Ham to the unexpected heights of fourth place. At Stamford Bridge, Allardyce was very much aware of the threat of his opponents and fielded a five-man midfield, with his two wide men, Stewart Downing and Enner Valencia, often appearing more like full-backs.

West Ham had employed similarly defensive-first tactics last season and frustrated Chelsea, and Mourinho in particular, to claim a goalless draw. But Boxing Day provided more evidence, as if it were needed, that this is a much improved Chelsea team. There is now more conviction about their play going forward and far more options at their disposal.

One of the key summer signings, Cesc Fabregas, was instrumental in Chelsea controlling possession from the off and passing rings around the bewildered looking visitors. Inside five minutes, Oscar missed a presentable chance when blasting over on his left foot following an error from Carl Jenkinson, before Gary Cahill twice went close.

The pressure was mounting, and when a beautiful one-touch passing interchange by Chelsea in the 31st minute required a last-ditch intervention to prevent a goal, it was clear West Ham were clinging on. From the resulting corner, they could hold out no longer. Fabregas’s near-post delivery saw Costa lose marker Kevin Nolan and flick on a header that Terry turned into the net from close range for his second goal in a week.

A fine save from Adrian just denied Nemanja Matic a second before the break, but the score line continue to fail to do justice to Chelsea’s level of control. West Ham briefly rallied at the start of the second half, but sense quickly returned that a second goal was just a matter of time away. Just past the hour mark it arrived in some style. Costa was exceptional throughout and highlighted his performance in getting the 13th Premier League goal of his first season in England. He showed both his technical ability, in befuddling three West Ham defenders with a jink onto his left foot, and then his ruthless touch in front of goal with a precise low finish into the far corner of the net.

The impressive Adrian in the West Ham goal prevented Chelsea from extending their lead. And, with Chelsea ringing the changes and understandably taking their foot off the gas ahead of matches against Southampton on Sunday and Tottenham on New Year’s Day, West Ham created their clearest chance of the contest late on when Morgan Amalfitano struck a post. But it could nothing to take away from the resounding nature of this victory.